low energy dwellings from the Highland Housing Fair
architecture - why low energy design?
Derry has 4 months a year with average temperatures above 16°C. London has 6 months with temperatures above 16°C. Hence Derry has a heating season of 8 months while London has a heating season of only 6 months.
A building can lose up to three times as much heat on a mild windy day compared to a cold still day. Derry has an average wind speed 50% higher than that of London, 6m/s to 4m/s.
Hence Derry has an average energy bill of £1,800 a year compared to London which has an energy bill of £1,200 a year.
Of the £1,800 annual bill, £800 goes on heating.
A low energy design house will reduce the annual heating bill to £100 a year.
does low energy design cost more?
On a typical house the additional insulation, air tightness measures and improved ventilation will add up to £5,000 to the cost of the construction over a traditionally built dwelling..
However the heating bill now will be around £700 lower giving a payback of around 7 years. The insulation and air tightness measures require no maintenance and will last the life of the building. The filter in the fan will need changed every 5 years or so.
Other benefits include:
A warmer home with more stable internal temperatures has not only lower maintenance costs but is more comfortable.
Improved ventilation that delivers filtered pre-warmed air to every room.
There is also the opportunity to reduce the size of your central heating system leading to reduced construction costs.
This 'Fabric First' Approach, concentrating on insulation, air tightness and ventilation is the most cost effective way to meet the requirements of the Building Regulations. (The up front costs are lower, the pay back is quicker and the maintenance costs are lower).
* costs are based on a 100m² (1,100ft²) semi detached dwelling. Larger or detached homes will cost more to run but have the potential to save more money.
low energy homes
Conventionally designed homes can be low energy (passive type) homes with heating bills of around £100 a year.