How do you get a building the size of a large, detached, high ceiling, one bed flat, to stay warm at 20c all day when outside is 2c, and use only 0.5kW per hour of heating energy?
It is possible but you just need to come across an architect, builder and landlord who work well together, want to do the best and get things right. We met that team.
We were asked by a commercial landlord to check the u-values of a small set of offices they had built. They wanted to make sure the tenants were comfortable, and the decision to move away from gas heating and reduce energy costs had delivered.
The designed insulation quality for the walls, floors and roof was 0.18W/m2K. This may not mean much to most people, but 0.18 is the best level of insulation recommended by the building regulations. The closer to zero the better. On average we see 0.55 in good quality homes.
We thought it would be impossible to get to 0.18. We were a bit worried our algorithms and sensors had met their match.
The good news is we measured the u-values at 0.178 w/m2K and when we looked at the energy consumption from the meter overnight, our heat loss calculations were bang on.
The numbers get even better.
At this level, for this size of building, you could run a small electric heater for 24 hours to stay comfortable and it would only cost £3. A bit extreme to keep the heating on all day, but if we had 12 months of winter, it would consume 4380kWh a year and emit 1.3 tonnes of CO2. The average home in the UK emits 8 tonnes.
The bad news is that you don’t see this level of quality every day. I wish we did but, on our travels, measuring old and new properties, we see massive gaps between what was specified and what was delivered.
In the worst case we have seen a u-value of 0.3 specified for the walls of a refurbished home, but we measured them at 1.6. The room never stayed warm, condensation was always present and the family were suffering with asthma. When we calculated the benefit of improving the walls, the energy bills would have halved and condensation would not have happened.
Let’s end on a high note. Net zero is well and truly achievable. You just need to know your numbers and have the right team.
Want to find out more? Contact us here.