Costs
So, will designing, constructing or refurbishing a building using sustainable principles make it prohibitively expensive? BRE and Cyril Sweett carried out a study (Putting A Price On Sustainability, published by BRE Trust, 2005) of the cost difference between the construction of four types of buildings (a house, a naturally ventilated office, an air-conditioned office, and a healthcare centre) to different BREEAM ratings. The conclusions are sure to surprise many and show that careful design from the outset can produce buildings that are more sustainable but at very little extra cost:
- An air-conditioned office building with a 'Very Good' rating is estimated to cost just 0.2% more than one with a 'Pass' rating. An 'Excellent' rating would cost 7.0% more.
- A naturally-ventilated office building with a 'Very Good' rating is estimated to cost 0.3% less than one with a 'Pass' rating. An 'Excellent' rating would cost 3.4% more.
- A house with a 'Very Good' rating is estimated to cost just 1.7% more than one with an 'Unclassified' rating. An 'Excellent' rating would cost 6.9% more.
The above information is reproduced from Putting a Price on Sustainability, published by BRE Trust, 2005 with permission from BRE.
Add the whole-life costs in however, and there's another factor to consider, and one that would be very interesting to occupiers - savings of up to 55%, 71% and 41% respectively were estimated for in-use costs throughout the life of the three above building types against buildings constructed to 2002 Building Regulations. These savings will be less when compared to the improved 2014 Building Regulations but with the benchmark (i.e. the Building Regulations) having been raised, the additional cost in achieving the BREEAM ratings will have come down since the BRE Trust/Cyril Sweett report.
The cost of incorporating sustainable solutions can be difficult to provide for ‘typical’ schemes, as constructors often deals with unique buildings and different local environmental factors, ways of operating and user requirements. The Home Builder’s Federation suggested that zero-carbon standards would have cost purchasers in the order of £2,500 per home over and above 2014 Building Regulations. However, some example costs of sustainable design solutions:
- PV cells - costs for installing a pv system have come
down significantly in the last few years as China has invested in new
production facilities; an average system of 2.7kWp would cost around
£12,000 including VAT at 5%, equating to £4,450 per kWp. 20m2 would cost approximately £14,000 to install on a house;
- PV cells - payback periods have fallen considerably and are now between 5 and 10 years when taking the feed-in tariffs in to account;
- PV cells - a 2.2 kWp system generating around 40% of a
household's yearly electricity needs, if eligible to receive the feed-in
tariff it could generate savings and income of around £900 per year;
- Solar thermal energy - has a typical payback period of 7
to 10 years but this will reduce if the renewable heat incentive scheme
is brought in for residential systems;
- Solar thermal energy - vacuum tubes for a 3 or 4 bedroom
house will cost around £4,000 to £5,000, providing 80% of hot water
during the summer and 20% in the winter;
- Air source heat pumps - systems cost from ₤3,000 to supply and install for a 3-bed house for low-temperature output (suitable for underfloor heating) to ₤5,000 for a combined hot water and heating system with output at 80°C, to £10,000 for a 5-bedroom house with output at 80°C.