Contact →

Tag: CLT

  • HPH395: How easy is it to insure a natural building? – with Dr. James Glockling

    HPH395: How easy is it to insure a natural building? – with Dr. James Glockling

    Dr. James Glockling explains how insurance works and outlines some of the challenges of insuring a natural building.

    Interview with Dr. James Glockling

    Dr. James Glockling began his career with the Loss Prevention Council, the insurers’ hub for studying fire, security, flood and other loss‑mitigation challenges. He later deepened his expertise at the Building Research Establishment (BRE), and then worked at the Fire Protection Association before setting out on his own as a consultant. His clients are wide-ranging, including insurers and even the military, helping them build resilience and mitigate risks in high‑risk scenarios—from multi-storey apartment blocks to the confines of a submarine. His work reminds us that, regardless of setting, safety rests on the same timeless principle: robust materials and well‑designed systems protect the people who depend on them.

    In this podcast interview we discuss everything from one-off homes to high-rise, multi-dwelling projects.

    Insurance protects the individual against disaster

    Insurance began as a collective safety net, allowing many people to share the cost of rare but catastrophic events. By pooling premiums, an insurer can compensate an individual when a loss occurs, turning an unpredictable disaster into a manageable financial outcome. This principle still underpins modern home and commercial policies, even as building practices evolve. Understanding insurance as a partnership rather than a pure expense helps homeowners see it as part of responsible building.

    “Insurance was originally set up as a means of protecting people against disaster, where you levy a premium on a large group of people to protect the interests of the individual.”

    Insurers have to weigh up a variety of risks

    Underwriters assess far more than fire. They examine the building’s use, size, occupancy, and any ancillary systems such as solar panels, battery storage, EV chargers, green roofs, or underground car parks. Factors like these may have an impact, so insurers request detailed information on design, materials and mitigation measures. The broader the picture they have, the more accurately they can price a policy and set conditions.

    One-off homes should be easier to insure

    As insurers always have to think about a complete loss and rebuild, having a single smaller property is a limited loss scenario. As the scale of a building increases so does the potential loss scenario.

    Self-builders often choose to construct with timber

    Estimated Maximum Loss (EML) is a key metric for insurers

    EML is the insurer’s worst‑case estimate of loss from a single incident, expressed as a proportion of the building’s total value. For a 20‑storey tower, an insurer might assume only four floors could be completely destroyed, translating to a 20 % EML. When new construction methods make fire spread more unpredictable, insurers often raise the EML toward 100 %, which drives premiums skyward or leads to outright refusal. Demonstrating a defensible, lower EML is therefore a key part of the underwriting conversation.

    Under‑insuring is a false economy

    Many owners underestimate the true rebuild cost of their property, declaring a lower value to obtain cheaper premiums. If a total loss occurs, the payout will only cover the declared amount, leaving owners with a significant funding gap. Accurate valuation, combined with robust risk mitigation, ensures that the insurance policy truly protects the investment.

    Insurance companies may have their own specialist areas

    James says that he used to live in a thatched home and that his monthly insurance premium was what most people would pay for a year. This is because if a thatched roof catches fire then the house will be a complete loss. However, NFU Mutual have made this their specialism and are seen as the go-to provider. This is because they understand the risks, know what conditions matter and have a history in this area.

    Water damage is the most common insurance claim

    Water loss accounts for billions of pounds of damage each year and occurs far more frequently than fire. Burst pipes, roof leaks and flood ingress can rapidly degrade timber, leading to rot, mould and structural failure. Early detection systems—wireless tape sensors, automatic shut‑offs—are increasingly expected by insurers, especially for mass timber projects where hidden water would otherwise go unnoticed for months. Proactive monitoring can therefore reduce both risk and premium.

    When it comes to timber, voids present a fire risk

    As timber is combustible, the design of a building becomes crucial. Voids can allow smoke, heat, and flames to spread rapidly, bypassing sprinklers and complicating firefighter access. Mass‑timber panels (CLT, glulam) reduce voids but may be subject to smouldering, which can persist for many hours and even lead to the flames reigniting. These behaviours force insurers to demand rigorous fire‑stopping, compartmentation, and sometimes hybrid designs to keep the EML manageable.

    A self build home that used cross laminated timber

    It’s essential that fire‑stopping is correctly installed

    Every penetration—pipes, ducts, cables—in walls and floors must be sealed with a fire‑stopping material. Missing or poorly installed fire stops create pathways for flames and smoke, dramatically increasing the EML. In light‑timber frames, the sheer number of voids makes comprehensive fire‑stop inspection essential. Regular audits, preferably by a dedicated Clerk of Works, provide the documentary evidence insurers demand. This may make a boring photo collection but it will be a valuable one.

    “I haven’t been to any fire in a building where I haven’t found the fire-stopping either missing or misplaced or just absent.”

    Hybrid designs with concrete cores satisfy insurers

    In high-rise buildings, combining timber with non‑combustible elements—concrete cores, steel columns or concrete plinths—offers insurers a tangible safety buffer. A concrete core protects against fire spread, provides a stable fire‑fighter access route, and serves as a flood‑resistant base. Such hybrids offer the best of both worlds, with the carbon benefits of timber while delivering the structural and fire‑performance assurances underwriters look for.

    Take photos during construction to provide evidence of good workmanship

    Even the best design fails without quality construction. Insurers scrutinise records of on‑site inspections, photographs and sign‑offs to confirm that fire‑stops, penetrations and material installations match the approved design. A diligent Clerk of Works creates a paper trail that can be presented during underwriting and later claims, reducing disputes and speeding up payouts.

    “Evidence is everything, and if there’s a Clerk of Works properly reporting on the job as it’s put together, then that can only be of great benefit.”

    Insurers steer away from complexity

    The industry uses six categories to describe the percentage of combustible material in a building. For example, Structural‑Insulated Panels (SIPs) are often highly combustible, pushing a project into the highest risk tier. When a building lands in the 100 % combustible category, insurers typically raise premiums sharply or decline coverage. Understanding these categories lets designers choose lower‑risk assemblies or offset risk with non‑combustible cores.

    The Mass Timber Insurance Playbook is useful resource

    The Mass Timber Insurance Playbook, co‑authored by Dr. Glockling and broker Philip Callow, lists 26 features that insurers evaluate in timber projects and offers practical mitigation strategies. It is freely downloadable from the Alliance for Sustainable Building Products website and provides a clear roadmap for architects, engineers and developers.

    Increasingly AI is being used in the underwriting process

    Insurers are increasingly using artificial intelligence to analyse loss data, identify patterns and refine risk models. By feeding detailed, high‑quality information from the construction phase into these systems, builders can help shape more favourable underwriting outcomes in the future.

    Find out more

    Mass Timber Insurance Playbook – free download from the Alliance for Sustainable Building Products

    Transcript

    Download a transcript of this episode.

    Please connect with us

    Subscribe, rate and review us on Apple Podcasts

    Follow Ben Adam-Smith on LinkedIn

    Follow Ben Adam-Smith on Bluesky

  • HPH305 : Building a Passivhaus with cross-laminated timber – with Mick Woolley

    HPH305 : Building a Passivhaus with cross-laminated timber – with Mick Woolley

    Mick Woolley explains how the use of timber was a key element of his award-winning Passivhaus bungalow.

    Interview with Mick Woolley

    For the last two years, Mick Woolley has been living in his Larch Corner Passivhaus which was the Small Projects winner in the 2021 UK Passivhaus Awards.

    His self build journey began following the loss of his wife. He had long held an interest in self building and took the attitude “what could possibly go wrong!”

    To watch the documentary about Larch Corner go to PassivhausSecrets.co.uk

    He broadened his search area

    Initially beginning his search in the south east of England to be closer to his two sons in Surrey, Mick found a lovely plot, surrounded by a vineyard, and just 30 miles away from them. But despite the proximity, it had taken an hour and a half to get there and was £450,000 before he’d even knocked the existing bungalow down. It was at that point he decided to abandon his search in the south east and opened up to looking at sites as far afield as North Wales and Cornwall.

    They made changes to the planning designs

    Mick saw a plot on RightMove, that seemed to be in a pleasant village location at the northern tip of the Cotswolds. Close to a National Trust garden and Stratford upon Avon, he felt he would be able to find enough to do in the area and was surprised when he managed to purchase it for around the guide price at auction. It came with planning permission for a single storey Passivhaus with a design that he admits probably didn’t appeal to everyone, and is why he thinks there wasn’t more competition in the bidding.

    Although not put off by the design, he was sceptical of its Passivhaus credentials and enlisted Mark Siddall of LEAP to re-work the plans. He did however want to keep it a bungalow to make it accessible for a family member who uses a wheelchair, but also because it future-proofed it for him too.  

    The original design had a lot of corners so they removed some of these and also had to raise the roof to ensure there was adequate head height for insulation. They swapped the entrance hall and study around to ensure a better flow into the house, and took out the many corner windows from the plans. Mark instead designed an arrangement of windows that came in 2 sizes: smaller ones for the bathrooms and bedrooms, and larger windows with seating elsewhere.

    Timber was an important element of the design

    Mick wanted to build using Cross-Laminated Timber (CLT), as much for the visual impact it provided inside as for its structural qualities. The bungalow uses 17 sections of spruce timber, which have 6 layers, are edge-glued, and don’t require an airtight membrane around the outside.

    The roof came with a cassette of insulation in it so the structure went up in two days, and had an airtight wrap over the top by the end of the third day. The walls are made of an I-frame structure with blown-in wood fibre, giving a thickness of around 600mm and a U-value of 0.1.

    The exterior of the bungalow has larch cladding.

    The foundations were pre-cut to size

    The building has a Jackon XPS foundation which was pre-cut to the required size and slotted together, with an XPS upstand that locked into the perimeter. This created its own formwork for the concrete pour.

    The flat roof has a camber of around 5 degrees for shedding water. On top of the insulation is a cold roof section of ply and bitumen that provides the finishing structure on which to put the green roof. Mick says he checks up there from time to time just to check that seedlings for trees and other unwanted plants haven’t blown in and taken root!

    He was keen to be hands-on

    With Mick being on-site throughout the build process he was keen to get involved in any way he could, so one task that he took on was the airtightness taping. His top tip for getting it into the corners is to ideally bend the tape in two in order to push it in and get good contact right the way through the junction.

    The straight lines of the 17 sections of CLT only took an hour to do, but all the other joints around the doors and windows took a lot longer!

    Mick employed Alan Clarke as his M&E engineer and he carefully designed the ventilation system so it could go through cupboards and be kept out of the way, but still accessible if needed. The full design with all of the MVHR kit was supplied as a single delivery, and Mick took on the installation of the pipework himself. Not having any experience of doing something like that, he did find it took him a very long time to put together!

    There is around 140 square metres of floating floor, which was designed to be laid to flow through without any junction strips at doors. His builder Andy took time to work out the geometry to ensure that boards were centred and wouldn’t end up with slivers at the edges, which Mick was then able to lay.

    Always make space for storage!

    Although Mick was adamant that he wanted to use CLT, he now realises that he could have been more efficient with materials and created the timber finish that he was looking for by using large sections of three-ply timber.

    If he were to do the build again, he would probably opt for a two-storey building, though still keeping a downstairs bedroom. He says that the UK housing stock is generally fairly deficient in terms of providing for the elderly and those with mobility problems, so designing at least one bedroom downstairs is really important.

    Mick says that going for a two-storey design would improve the form factor and use a lot less insulation. It is also more efficient in having less foundations and roof.

    Lack of storage space is often a real problem in typical new build homes, but Mick is delighted at the amount of space they designed into his home, including a large storage wall. He also has a double garaged sized shed, although this is currently housing lots of off-cuts of CLT and three-ply materials that are waiting to find a home!

    He emphasises why it’s always a good idea to build into the loft as that’s also potential space that can be used for storage.

    Images copyright Mark Siddall LEAP

    Find out more

    To watch the documentary about Larch Corner go to PassivhausSecrets.co.uk

    Check out the website of LEAP

    Follow Mick Woolley on Twitter

    Follow Mark Siddall on Twitter

    Please connect with me

    Subscribe, rate and review the podcast in iTunes

    Rate and review the podcast on Stitcher

    Like our Facebook page

  • HPH274 : An innovative cork house, designed for disassembly – with Matthew Barnett Howland

    HPH274 : An innovative cork house, designed for disassembly – with Matthew Barnett Howland

    Award-winning Cork House was the world’s first to use a solid cork construction system. Matthew Barnett Howland explains the concept and how he managed to build it himself.

    Matthew with Cork House collaborator Dido Milne – Copyright Magnus Dennis

    Interview with Matthew Barnett Howland

    Matthew Barnett Howland is Director of Research and Development at CSK Architects in Eton. He has always had an interest in making things, as well as designing them, and in 2013 he teamed with academic and industry partners to research and develop the solid cork construction kit, of which the Cork House is the first pilot.

    Copyright David Grandorge

    The idea was to design a building with respect to its material ecology

    The process of designing the Cork House wasn’t to try and build a house made from cork. Instead it developed from a general dissatisfaction about how modern houses are constructed in the UK. They have a complexity at almost every stage of the building’s life cycle:

    “From the resource stage and landscaping packs; through to even the design stage, specifying different materials with different properties and so on; through to on-site sequencing of trades, interfacing between trades; through to the performance gap that you almost always get in houses where they always perform less well than they’re predicted; right through, particularly most importantly probably, to the end of life scenario where you have a destructive demolition.”

    So one of the project’s main motivations was to think about the material ecology and then develop the architecture from that, rather than the reverse.

    A holistic design approach was used

    The design of a house is typically the result of a response to site characteristics, a client brief, planner’s input, engineer involvement, a construction that will pass building regulations, followed by a pricing and value engineering process. Inevitably there tends to be a granular, rather than holistic approach to a project. What the Cork House allowed Matthew to do was be the client initiator, researcher, designer and builder, allowing him a single-minded and holistic way to approach it.

    The brief was for a building envelope that used a single bio-renewable material

    The Cork House was specifically sited at the rear of their existing house, at a bottleneck between two gardens that creates a threshold space and articulates the junction between the two.

    Copyright Phil Broom

    The brief was driven by a desire to find out whether they could make a building envelope, walls and roof out of a single bio-renewable material that would fulfil all the functions and performance requirements of the modern building envelope.

    He contacted Innovate UK and EPSRC (Engineering and Physical Sciences Research Council) and together they created a research team of academic and industry partners, who in the space of two and a half years, tested, prototyped and developed the proof of concept for the solid cork building envelope.

    Cork possesses a range of ideal qualities and uses

    The team worked with the Portugese company Amorim, who are the world’s biggest manufacturer and supplier of cork products.

    Cork comes from the bark of the cork oak tree. The majority of a harvest is used as bottle stoppers, while another part of the industry uses granulated cork mixed with a polyurethane glue to make a range of products.

    The waste from these industries ends up being made into expanded cork. The cork waste is granulated and heated to around 360°C with dry steam passing through it. The granules expand and release a natural resin, suberin, which melts and as it cools it re-bonds the expanded granules back together again. The result is a fully bio-renewable and bio-degradable product.

    Cork has a number of qualities which made it ideal for the range of uses required for this project: the structure, being watertight, airtight, insulating, internal and external finishes.

    The life-cycle of the house was an important consideration

    The house has been designed so that if a time arrives when it should come to the end of its usable life, the materials can be easily recovered for reuse or recycling.

    There is no mortar or glue between the cork blocks, and the connections between the timber elements are all bolted and screwed, meaning that everything is accessible and demountable.

    Anything that can’t be reused or recycled, being pure cork, can be granulated and put back into the soil to biodegrade and be a soil improver.

    Research was carried out to test performance

    Prototypes were made and tested in-situ for the cork’s airtightness and weather performance, which aided the research and knowledge for the construction process.

    They also undertook a range of lab tests. These tested for performance in wind-driven rain and fire protection, as well as a number of structural capabilities.

    The architecture, spaces and forms are as a result of the cork properties

    For example, the pyramidal roof shapes came about from a series of decisions about using cork.

    “It works best in compression, we don’t want to use glue and mortar for disassembly reasons, and the wall works with the tongue and groove system so a logical consequence of that for the roof is rather than introducing a new set of materials and systems that would introduce complexity, you offset this wall system using these solid blocks of cork to take the load through them. So, the form is a result of those considerations and those factors.”

    It’s built off removable steel screw piles

    The motivation for the removable steel screw pile foundations was the ability to return to a pristine site if the building was ever dismantled and removed.

    On top of the foundations, a 300x100mm timber beam was bolted all the way around the perimeter. CLT (Cross Laminated Timber) floor plates were dropped onto the ring beam giving a solid timber deck with cork insulation underneath.

    From there, prefabricated cork blocks (1268 in total!) were tapped down and held with friction to build the walls. This process was very quick and easy until it came to where they interfaced with the timber ring beam and valley beams.

    The vertical load in the house is taken down to the timber slab via the cork. The lateral and sheer loads to stop the house folding over in the wind are taken through a sort of timber ladder beam at eaves level. Matthew describes trying to ratchet strap and clamp the prefabricated timber elements with the prefabricated cork elements as being particularly challenging.

    There is a limited but consistent palette of materials throughout

    They have used spruce tri-ply and TILLY board for the built-in joinery. The bed, sofa and dining table are made from reclaimed spruce CLT, the kitchen stools are made from storm-felled oak, and the floorboards are oak unplaned timber screwed down into the spruce CLT floor.

    Copyright Magnus Dennis

    Variations to this are with the solid brass worktops, a bespoke folded solid brass bath and basin, and copper for the gutters and downpipes. All are unlacquered, pure material that can be recycled back into the manufacturing chain.

    Solutions had to be found for the plumbing and electrical work

    With solid walls that don’t have cavities or voids to hide services behind, everything is exposed and had to be thought through carefully.

    The bathroom is a self-contained independent solid CLT box structure which acts as a hub for all the services, and the CLT floor panels were pre-routed to accommodate pipe runs under the floorboards. The built-in furniture and structural wardrobes were also pre-routed for service routes.

    Matthew had a dual motivation for doing the project

    Firstly, it was to build a house which they could use themselves, and secondly it was to use their skills in design and research to respond to some of the pressing issues of our time.

    He started designing the house with his father, who was also an architect. When his father passed away he felt that it was a good use of the money that his father left him to work full-time on it to complete the project. Matthew estimates he worked on the project full-time for around five or six years.

    He is keen to continue the research and learning

    With work completed on the house there have been areas that they’ve had to return to. One was to add a foam tape on the internal face of the block joints to improve airtightness, which Matthew says would have been nice to achieve without a foam based product. And on the roof they have introduced cedar weatherboarding to help shed the rain, otherwise it wasn’t watertight just as a pure cork structure.

    Matthew enjoyed the process of research and learning, and the way of going about things in terms of conceiving and developing an idea, putting together a team, getting the funding, lab tests, prototypes, getting it through building control, etc. He would also be keen to do more work around life cycle issues, which they’re currently doing on another cork project for a client, but also look at it with other low carbon materials such as timber or stone.

    Copyright Ricky Jones

    Find out more

    Visit the website of CSK Architects

    Check out Matthew Barnett Howland’s website

    Transcript

    Download a transcript of the interview with Matt-Barnett-Howland.

    Please connect with me

    Subscribe, rate and review the podcast in iTunes

    Rate and review the podcast on Stitcher

    Like our Facebook page

    Follow us on Twitter

  • HPH227 : What’s the best way to build an airtight structure? – with Paul Jennings

    HPH227 : What’s the best way to build an airtight structure? – with Paul Jennings

    Air leakage expert Paul Jennings looks at how best to achieve that all important airtightness when using particular construction methods.

    Interview with Paul Jennings

    Paul Jennings is an air leakage expert with over 25 years experience. In our previous interview with him he explained how to achieve airtightness in low energy buildings. He also appeared in our documentary “The Future of Housing – and How Airtightness Can Help”, taking a look at housing construction quality and building performance to see how they could be improved.

    For this podcast, he looks at some of the issues with achieving airtightness in different construction types.

     

    Cross Laminated Timber (CLT)

    Paul recently tested a bungalow that was built using Cross Laminated Timber. The airtightness is essentially in the timber, and in this bungalow there were up to 8 laminations in each of the panels. The roof was a sandwich panel with layers of lamination, insulation, and more laminations on top. With the panels being larger than standard OSB boards, there is less taping involved. Each panel is also very strong, and strengthened further when screwed together. The taping goes where the panels butt up to each other, around windows, ventilation ducts, sun pipes etc. Once you have taped to the timber you have airtightness.

    Paul is starting to think that there is no need for a membrane on the outside. The CLT doesn’t meet insulation values but he thinks it’s perhaps easiest to insulate it externally and make it airtight on the inside.

     

    Structural Insulated Panel Systems (SIPS)

    Paul has experienced very good results with SIPS panels, which he feels have the potential to be very airtight. So far he hasn’t seen anyone using the airtight OSB as one of the faces of a SIPS panel system, which he thinks could improve it further.

    He explains there is a difference in results depending on whether foam is injected into the pre-made box, or whether a piece of foam is cut and put into a section of wood which then has sides added. The latter won’t be as airtight.

    SIPS panels can be a problem on site if they get saturated with water as they take such a long time to dry out, and the airtightness tapes do not adhere properly.

     

    Masonry Construction

    Masonry construction ticks the box of being a system that normal builders are used to building, where most materials can be sourced from a standard builders’ merchant. Paul offers Denby Dale Passivhaus as a great example of this.

    Paul explains that any construction with a cavity in, is a weakness for airtightness. If air can move laterally it can get around things and leak where you wouldn’t expect it to. He prefers a masonry build that has a masonry wall which is ideally wet plastered for airtightness on the inside, with insulation and render on the outside.

    “Because at that point, you have to have a continuous hole from the inside to the outside. You can’t have a hole through the inner leaf, then air moving in which way it likes in a cavity and then coming out somewhere else. It’s more robust for airtightness.”

    Paul points out that almost every masonry build has a timber frame roof, so as soon as you’ve opted for masonry construction you’ve doubled the number the number of build forms in your house anyway.

    Paul emphasises how the more complicated a build is, the harder it will be to achieve the airtightness. There is greater scope for people on site getting confused, doing the wrong thing or not checking details properly.

     

    Modular construction

    This isn’t a widely used construction method in the UK but there are increasing numbers of companies trying to develop it. The benefits of this method are that production has less of an issue with weather, shortage of trades people etc, than for on-site construction. The ones Paul has seen have been generally at a prototype stage with initial positive signs and great potential. He believes they will have to be built to be incredibly robust, as otherwise they wouldn’t survive being craned on to a lorry, driven to the site and craned off again.

    One of the big advantages of modular construction is there is less time spent on site, which means less financial impact from weather delays, and less overheads on things like site supervision, site cabins and toilets.

     

    Airtight OSB is gaining in popularity

    The trend that Paul is seeing at the moment is that membranes are losing out to the airtight Oriented Strand Board (OSB) and, for refurbishment particularly, to blowerproof paint. The most popular he currently sees in the market, and which he thinks are proving to be very successful, are the Durelis and the Propassiv.

    “At the same time, the refurbishment market is a bigger market than the new build market. We need to tackle refurbishment and we need to tackle it better. And we’re not. We’re learning lessons but really we’re taking our time over getting it and I don’t think we can afford that time.”

     

    Choose the right tape for the job

    Choose the right manufacturer, and the right tape. For example, don’t try and use 50mm tape to cover a gap of 60mm. Choose one that is wide enough for the gap.

    Paul believes the two best products for airtightness are produced by SIGA and Pro Clima. But no matter how good the tapes, most important of all is how well they’re applied.

     

    Plan early and get advice from the experts

    “You really want to get your designing done early, get your planning done early and then don’t mess with it. Because every time you change it, there will be unforeseen consequences. Usually those will be things that make your airtightness worse or harder at least.”

    Paul encourages self builders to take advantage of the Passivhaus Open Days and talking to the people who have built them. There are also the AECB and UK Passivhaus conferences that people can attend and find out more about the network of experts.

    “There are networks of people and a lot of them are very committed people. They give their time, they give their energy and they often don’t charge as much as they should for it, because they believe in it.”

     

    Find out more

    Visit the website of Design Buro

     

    Transcript

    Download the transcript of the interview with Paul Jennings.

     

    Please connect with me

  • HPH177 : Redeveloping a brown field site for a contemporary home – with Ruth Butler

    HPH177 : Redeveloping a brown field site for a contemporary home – with Ruth Butler

    Architect Ruth Butler shares the story of building a contemporary Passivhaus on an overlooked, brownfield site.

     

    Interview with Ruth Butler

    Ruth has been an architect for a number of years and was previously a partner at a practice in London. Part of the reason that she and her engineer husband left London for the south coast, where she has been running Ruth Butler Architects for several years now, was for the opportunity to build their own home.

     

    Planning permission on a previous plot helped fund this project

    After a long search they found a back garden plot but weren’t able to get planning permission on it for what they wanted to live in. Instead they decided to opt for a design that would get planning permission, and sell the land for a profit which they could use to bankroll the first few months build on their new site.

     

    Clearing the brownfield site was an opportunity, rather than a constraint

    The site had been the regional headquarters of St. John’s Ambulance and had a big, robust garage building on it which used to house the ambulances. The existing garage was knocked down and the component parts recycled into the build, with the brickworks being recycled into the hardcore, and the steel beams being used to build their own garage.

    One of the most significant constraints was that it was surrounded by 13 different neighbours, who were all keen to challenge anything being built on the site because of concerns for their own privacy. Ruth approached the neighbours and made it clear they were a family, not developers, and were keen to make their future there. She emphasised that she wasn’t interested in overlooking them, any more than they weren’t interested in being overlooked by her. By making a model of the proposed building and neighbouring properties, they were able to demonstrate how the property would look and how it would impact on the surroundings.

    Ruth and her husband enjoyed the challenge that the privacy issues and clearing the brownfield site threw up:

    “The more constraints, the better the design has got to be to overcome them.”

    Preparing the planning application took around a year, with getting the neighbours on side and getting the design right. The planning authority were supportive of the application, despite being a contemporary piece of architecture in a traditional setting, and they were granted planning permission without any problems or delays.

     

    Design should complement the site and complement the way you want to live

    Originally they would have liked a single storey dwelling, but the site wasn’t big enough and they also needed the height to shield some of the views from neighbours. Instead, the house has an L-shaped design which encloses a walled, entirely private courtyard garden. Traditionally entrance halls were used for draft-proofing, but with a Passivhaus that function isn’t required so they were able to re-think the entrance to their home. As you enter the front door you come directly into the kitchen, with the dining room and living room being at either end of the L-shape.

     

    A pre-fabricated structure was chosen for a faster build

    After selling their house to fund the project, they needed to rent while they were building so it was important to build quickly. They chose a cross-laminate timber structure which was pre-fabricated in Austria. It was erected and weather-tight in just 4 days on site. Completing the interior fit-out and exterior cladding took the whole build process to a total of 7 months.

     

    The design challenged Passivhaus stereotypes

    Although Ruth and her husband had been interested in Passivhaus they weren’t entirely sure they would be able to achieve it on this build. The site demanded a substantial size of building and their completed design is at least double the Passivhaus form factor rules. To ensure they have enough light in the single storey elements they have used roof lights and they have added more insulation to the roof and walls than they might otherwise have done. Where they have a large amount of glazing to create a good indoor-outdoor flow they have used sailcloth for shading which can be taken down in the autumn and deployed when it is needed.

    The house has a Passivhaus cat-flap which is super-insulated and programmable to and operated by an ID chip on the individual cat. They don’t come cheap though, at around £1,800 installed!

    “I think it’s really important that Passivhaus, you can prove that you can do good bespoke site-sensitive designs and still meet the Passivhaus standard. I don’t want to see a world full of very square, boxy solutions to Passivhaus designs, I want to see buildings that respond to their sites.”

     

    The Landscape Architect was given design freedom

    Ruth says that her clients would ideally give her a clear brief, knowing what they want to achieve and their functional requirements, without second-guessing what the design of their building might look like, as that essentially is part of her role. So when it came to the landscaping she was happy to give her Landscape Architect John Brooks a clear brief and the freedom to design it how he wanted.

    “But I had been to see some of his work and I had made some assumptions in my mind as to how I thought he might tackle it and he entirely surprised me and came up with a design that took my breath away really.”

     

    Ruth shares some helpful tips…

    • It is important to design the inside and outside in tandem.
    • Get the team right in the first instance. Their contractor hadn’t done Passivhaus before but that wasn’t important to Ruth. What mattered was whether they had the right attitude, and that applies to the whole design team.

     

    …and lessons learned

    If doing the project again she would:

    • Change some of the technical details, such as instead choosing a pre-fabricated insulated slab.
    • Use cross-ventilation in the bedrooms. The bedrooms are currently slightly warmer than she would like them to be.

     

    Find out more

    Visit the website of Ruth Butler Architects

    Follow Ruth Butler on Twitter

    Ruth’s building contractor – Nicholas Coppin Limited

    Ruth’s landscape architect – John Brooks

     

    Transcript

    Download a transcript of the interview with Ruth Butler.

     

    Please connect with me

  • HPH107 : What Does it Take to Create Sustainable Neighbourhoods? – with Jon Broome

    HPH107 : What Does it Take to Create Sustainable Neighbourhoods? – with Jon Broome

    Jon Broome of Jon Broome Architects explains his work with community self-build groups, and the development of a sustainable neighbourhood he is currently involved with in Lewisham.

    JB

     

    Interview with Jon Broome

    Jon first got involved in self-build projects back in the 1970s with Water Segal, the pioneering designer of lightweight timber construction for self-building. Since then he has continued working with groups in South London and elsewhere building housing co-ops, and is currently involved in a project with a Community Land Trust development in Lewisham.

     

    The Influence of Walter Segal Has Yet to be Fully Realised

    Jon estimates there have been up to 300 houses in the UK which have been inspired by Walter Segal’s principles of simple and economical building.

    “And that opened up a whole range of possibilities which I think are yet to be realised fully actually.”

    Walter's Way, Lewisham - the first group self build project to use the Segal method of construction
    Walter’s Way, Lewisham – the first group self build project to use the Segal method of construction

    Since the 90s however, interest has waned with what Jon sees as people’s preoccupation with building trends changing, such as pre-fabricated housing or custom building.

     

    In the UK we Struggle to Create Neighbourhoods

    Jon is concerned that buildings should perform well, be low energy, sustainable, comfortable, light and airy and well ventilated. These are all things which he says we can do, however in the UK what we are less able to do well is create neighbourhoods which are convivial and support comfortable social living arrangements.

    Currently the private sector deliver what a lot of people want and can afford, and the public sector deliver a limited number of affordable homes. Jon says there is a big area in between which doesn’t necessarily satisfy what people want. They tend to be of a price they can’t afford, not very well built, small, not energy efficient and generally not desirable. The idea of sustainable neighbourhoods is that it brings good building together with residents who can have control over the major decisions affecting how much they cost, and how they’re designed and built.

    “It’s to do with low energy building. It’s to do with sustainable development. It’s to do with, I don’t know, just living in a convivial way in a city which normal housing arrangements don’t encourage I don’t think.”

     

    A Community Land Trust Might be an Option to Consider

    Jon is involved with the RUSS Community Land Trust development in Lewisham. They have recently acquired a site from the local authority in Lewisham and will be making a number of different options available, including affordable rental accommodation, and shared ownership and shared equity dwellings with buy in between 25% and 80% ownership. The Community Land Trust retains some of the equity to ensure that the development remains affordable and that dwellings don’t migrate into the private sector where escalating prices would inevitably follow.

    They are encouraging a high degree of self-build because of the benefits it can produce, including significantly reduced costs together with a huge amount of self-confidence and sense of self-achievement from designing and building your own home.

    “I think what matters more than anything else is having a feeling of being in control of their destiny and knowing how the building is and how and why it’s designed in the way it is, how it can be changed, developed, improved. It’s just being in touch with your immediate living surroundings.”

    As architects for the project, Jon Broome Architects have started by working up ideas of what affordable housing means to who and aligning the cost of people’s housing with their income, rather than with the value on the open market. They are ensuring the houses will be cheap to run and concentrating on the sustainability of the development as a whole with bike provision and shared electric cars. They are making sure it is a mixed community of congenial people who want to live in a supportive environment. And while the self-build approach will reduce costs, it will also create opportunities for people to acquire skills and improve their employment prospects.

    They will be taking all of this and translating it into a design brief and make plans for the flats and houses, method of construction (which also needs to be capable of unskilled people on site), contractual arrangements, legal frameworks, financial arrangements, building standards, planning etc.

     

    Satisfaction is Not Prioritised by Developers and Policy Makers

    While there are undoubtedly people out there who don’t want to get involved in a process which can be complicated and time consuming and are happy to buy a standard developer home, there are others which generally aren’t catered for who want the satisfaction and long lasting benefits of quality of construction, design and maintenance. For those people generally the opportunities to design and build for themselves are all too rare.

     

    Self-Provision of Housing on the Continent Remains Strong

    Jon has recently been to Germany and estimates that over half of housing is of this kind. In Berlin he thinks around 10% of new housing in the city is produced by groups of people getting together to design and commission the housing, but not necessarily building it. The process is aided by the city government which holds regular meetings for interested people, and is encouraged by the financial systems which are willing to lend on schemes that they know are being professionally managed and developed.

    Land can be compulsorily purchased by local authorities who then put in the infrastructure and sell it at a profit which gets ploughed back into housing development to groups who then build. There is a fixed price for the land and the successful party is the one that can bring most quality to the development, such as social provision, value for money, quality of dwellings etc.

    Jon feels that important lessons can be learned from this continental approach, in terms of how groups and design processes are organised, about communicating and controlling costs effectively.

     

    What Matters is Getting Developments on the Ground That You Can Experience

    Jon agrees that this way of living won’t be for everybody, but there’s a significant number of people to whom it suits very well. By getting successful developments on the ground that people can look at and demonstrate what the possibilities are in an urban environment, Jon is hopeful that people will see that there’s something in it.

    Jon cites the example of Ashley Vale in Bristol, as being a similar case of people having a vision and determination to improve their housing circumstances.

    While the local authority in Lewisham have been supportive, the process of securing land for the development has been lengthy and costly. The site is also not without its difficulties and while the price for the land is not what it would be on the open market, it recognises the social benefits and what will be involved in terms of energy standards and sustainability.

    We’re keen to follow how this development progresses, so keep an eye out for part 2 at some point in the future!

     

    Find Out More

    Follow Jon Broome Architects on Twitter

    Jon Broome Architects

    Rural Urban Synthesis Society 

     

    Transcript

    Download a transcript of the interview with Jon Broome.

     

    Challenging Times on a Build

    Ben is keen to hear from other self-builders who, for one reason or another, have hit challenging times on their projects. He would like to collate these experiences in a blog for others who might be facing similar issues and to give encouragement to keep persevering with it! Please get in touch if you would like to be involved.

     

    Please Connect With Me