We catch up with Alex Baines, a Passivhaus consultant who you may remember from episode 74. We spoke to him then about how gaining support for his semi earth-sheltered rural self-build from his local community helped him achieve the necessary planning permissions. Almost a year on we spoke with him again to see what progress he has made on the build so far.
Excavation Work Took Almost a Month
Being semi earth-sheltered to comply with planning restrictions, a very large hole was always going to be needed! Over the winter it took 4 people, a 20 tonne excavator, an articulated truck and a roller to dig down 5 metres. They actually dug out around twice the volume they needed to prevent the sides from collapsing. Their ethos is to try not to throw away anything on site so everything they excavated will be utilised, whether that be earth for backfill or turning the rock into fixtures and fittings for the house.
Digging Below the Water Table Has Meant Extra Precautions Were Taken
Digging up to 3 metres beyond the ground water level, Alex had been expecting the hole to fill up constantly but that hasn't been the case. Instead it's had a dribble of water occasionally going into it in two corners, although a fair amount is trapped in after rain. To get them through the construction phase they bought a £100 pump to remove water from the hole, though it hardly needed to be used during the summer months.
There is a double layer waterproof DPC membrane going the whole way around the ground perimeter. On top of that they're also using waterproof concrete under ground.
The Stages So Far:
- A layer of hardcore to get a level base
- Poured a very thin blinding layer of cement-concrete
- Waterproofing line laid
- Base poured
- Steels in and east, west and north walls built out of ICF (Insulated Concrete Forms) and filled with concrete, followed by the south side
- Roof on
The Building is Designed to Make the Living Spaces Easily Adaptable
While there is a lot of concrete going into the building, Alex feels justified because he is creating a home that should last for centuries and be flexible to the changing needs of its occupants. The steel and concrete support the structure and there are no internal load bearing walls. The result is that internal dividing walls can easily be added or removed to reconfigure the space according to the needs of the owners and styles of the time. The other benefit of the concrete is its absorbency of heat, which they hope to retain throughout the winter. Researchers from the University of Loughborough are installing monitoring equipment to see what the effect of an ICF system is in terms of the latent heat in the building.
Alex Wouldn't Ever Recommend a Client Use as Much Glazing as he is on the South Elevation!
They are not having glazing on the east and west sides, and very little on the north. They are using the glazing on the south to try and take in heat and light to be retained in the concrete core.
“From a passive nature I'd much rather design the windows to be the right size that you don't actually need any external blinds or any improvement to the actual glazing in terms of improving its g-value for solar glare control. But here we do have the views, we do have the space and we do have the height. And architecturally and from being on the site it didn't make sense to restrict the window size.”
With slight changes to increase the height of the windows they are still working on calculations for how best to install the external shading.
There will however be areas at the back and downstairs of the building that will not get much light, however these have been designed to be the rooms which would need it least and Alex is not concerned that this will be a problem.
Work is Likely to be Delayed Until Further Finances are in Place
Generally the finances have been on track, apart from early additional costs at the excavation stage. Extra time was spent on the equipment hire to try and break through the rock, and they were advised to reinforce the concrete to avoid the effects of heave in the ground.
Alex left his work 3 months ago and the savings that they hoped would see them through to the windows in / watertight stage are unlikely to stretch that far. They have the details and spec sorted for most of the remainder of the house so once Alex is back in work the mortgage should be agreed and they can move to progress works quickly.
Borrowing money from family is not an option that Alex would consider. He believes it could be detrimental to relationships and he wouldn't feel comfortable with the situation.
While the Design has Caused Additional Costs, They Would Not Have Got Planning Permission to Build a Standard House
Alex bought the land from his mother. As it is in a rural area they were bound by very strict regulations and had to work hard to achieve planning consent. Building a standard house would never have been an option that would have been approved. The result of planning approval is that the land has now increased in value from £16,ooo to around £300,000. Alex describes a situation where they could have built a standard house for a lot less money in a village setting, however the majority of their funds would then have been spent on the land purchase, leaving very little for the build.
Personally and Professionally the Build Has Been Massively Rewarding
Professionally Alex has learned a huge amount from being on site every day and seeing things that as a consultant you just don't get to see. He has broadened his knowledge by speaking to experts on site and working through problems – all skills that will be useful for future client builds, not just his own.
On a personal note, Alex enthuses about being around to have the opportunity over the last few months to spend time with his young children and see defining moments in their development that he would otherwise have missed. While the delays on the building are frustrating, Alex wouldn't have changed the situation, saying “actually there are things that I've gained out of it that I actually don't want to give back.”
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