The Thomas's had extended their bungalow three times over the 20 years that they had lived there, but felt it was time to move on. They didn’t want to relocate far, but struggled to find somewhere suitable nearby. This led the family to do something quite radical… demolish their existing home and build a new one in its place!
“Our home was old and draughty and needed a fair bit of work done to it,” explains Lynn Thomas. “We knew the plot of land the house sat on was valuable so decided that a low energy self-build was the way forward!” The old property was valued at £350k – less than they thought – confirming any doubts in their mind that a custom build was the answer.
“We saw a video about low energy consumption homes and decided that ‘green’ was important to us,” continues Lynn. “We did a lot of to-ing and fro-ing with an architectural technician to come up with the final design.” The family decided on high levels of environmental comfort, incorporating solid concrete floors with masonry internal and external walls.
The family wanted to start work in June 2012, but faced a major problem with disconnecting gas and electricity from the original bungalow. They ended up having to wait for two months for the utilities to be cut off and moved even though they had already left the property. They also found it emotionally draining to watch the home in which they had lived for so many years be knocked down, especially considering how long they had to wait before it was done. The utility supplier compensated the family £250 as a result of the delays, but this compared poorly with their extended rental which totaled over £2000.
The logistics of organising all the different trades was also a challenge as the couple decided to deal with the building control themselves. “My husband has a great deal of experience in energy saving products, so we were able to specify certain products ourselves,” continues Lynn. The H+H Celcon Blocks for the internal and external walls and foundations, the roof tiles underlay, external wall insulation, underfloor heating, woodburner, windows and doors, and more, were all specified by the couple.
After the connection of gas and electricity there was a lengthy warm-up process for the underfloor heating, taking the recommended ten days. Unfortunately, this caused substantial amounts of water vapour to be released, much of which condensed in the loft. Although this was only a temporary problem, experience shows a need for care. Advice for other self-builders at this stage is to ventilate the property as much as possible and ensure there is a good air flow through the loft from the eaves, which can easily be blocked by poorly fitted loft insulation.
There were other costs that the family hadn’t originally budgeted for which began to add up. Building Control requested the foundation width and depth should be increased, but they hadn’t budgeted for landscaping costs or the decorating contractor that they decided to use. This, along with the extra £2000 in rent came to quite the unexpected figure. “In hindsight we could have saved money by staying in the house until it was ready for demolition,” Lynn adds.
The H+H aircrete used has strong sustainability credentials: not only does it provide excellent thermal and acoustic insulation and contributes to air-tightness but, being manufactured from up to 80% recycled materials, it is sustainable both in manufacture and in use.
“Solid wall construction has been growing for several years in the UK market,” explains John Churchett at H+H. “As solid wall eliminates the requirement for cavity ties, cavity closures and cavity trays enabling a simpler build compared to cavity wall construction. The versatility of this method of build enables various external finishes to be applied; external insulation can be changed to achieve the required thermal performance. The product’s good thermal mass helps in reducing temperature variations within the property allowing the home owner a more comfortable living environment.”
“This was the first time I had built a house with external wall insulation, although I am very familiar with block-work building,” explains principle contractor, Chris Page. “The single skin went up very quickly and I am very pleased with the end result. I would love to build another house like it.”
The perfect fit
The final house fits neatly into the plot, with the local community seeing it as an improvement on what was there. It faces east, which isn’t the conventional positioning for a passive house, however it does have a very low energy consumption. It achieved a level B in the energy performance certificate because of the amount of insulation and has a mechanical ventilation heat recovery system which regulates the air temperature in the house. The underfloor heating system also helps greatly with heating the house.
The new self-build boasts everything that the family wanted – large living spaces, four double bedrooms and a light, open plan feel – you might even forget you’re on the same plot where the pre-war bungalow once stood. “The wow factor is the brightness of the house’s exterior as it’s now clearly visible from the road,” continues Lynn. “We recently had road works and most drivers pulled up in the queue opposite the house and spent a long time looking at it. My son also loves the front door that shuts like an airlock!
“My favourite thing about our new home is the comfort factor. It is so warm and homely, there are no cold spots at all. Looking back, the only thing I would change was opting for a wood burner. The underfloor heating ensures the house is so lovely and cosy that the log burner often makes it too hot!”
The Thomas’s have learnt a great deal from their self-build journey and advise others to not make the same budgeting mistakes that they did. “Plan, plan and plan again before doing anything,” recommends Lynn. “Get all of your figures down on a spreadsheet at the start showing all outgoings and how much of the budget is left and maintain this throughout the entirety of the project. Every time you buy something log it on the spreadsheet. Also, make sure you organise anything concerning utilities well in advance, double check and even triple check just to make sure everyone involved is thinking the same!”