Matriz de eventos de intervención 202 8.18 Matriz agrupada conceptualmente

This innovation is summarised as the costing of combinations of available technologies to contribute to the CO2 reduction target of 44%, having designed affordable thermal efficiency into the fabric of the buildings as expressed in Innovation 1. The regulatory driver is Ene 7 (Low carbon technologies) of the Code for Sustainable Homes, and the client’s Design Guide provides the immediate framework for the potential options. The innovation is evolved by the architect and the contractor, as the Systems Integrator and the innovation infrastructure of the project, and the innovation, as a combination of existing technologies, is defined as incremental.

The client’s Design Guide specifies mains gas, where available, as the preferred primary source of space and water heating and, where the combination of this within a well-insulated home does not meet the DER standard, alternative sources are ordered as follows28:

1 Solar hot water generation 2 Air source heat pumps 3 Ground source heat pumps 4 Biomass communal heating

The ongoing useful life, maintenance cost and ease of use for residents of these options is to be considered with Asset Management and Housing Management colleagues, and ‘a single system of higher output is preferred to the use of multiple technologies’ (client’s Design Guide, 2010:10), thus innovation in energy options to meet Code 4 requirements for Smith Lane needs to accommodate this guidance.

28

The use of solar power to generate electricity is not included in this list. This apparent omission may be taken as evidence of the rate not only of the development of solar panels as a supply chain product, but also the knowledge and acceptance of these as a potential realistic source of power at the time of the case study interviews.

160 For Project A, the client’s Design Brief (2008) defines preferences for ways of meeting Ene 7, from which the contractor and architect developed a range of solutions. The potential options for meeting the specified TERs (Target Emission Rates) were specified by the architect for the contractor to cost as part of their financial assessment. The architect’s approach combines the ‘fabric first’ principles championed by the client and contractor with additional technologies and the architect’s energy options schedule at Appendix 4.5 reflects a mix of increased insulation, high specification gas heating and renewable energy sources. This is defined as innovative in that the approach, of assessing and summarising different potential mixes to meet Code criteria Ene 2 (building fabric heat loss parameters) and Ene 7 (renewable energy sources), is new to the architectural practice and adds value by extending expertise in energy- efficient technologies and the cost-effective combinations of these.

The architect’s energy options spreadsheet at Appendix 4.5 is based on four sample properties at Smith Lane of different sizes and orientations, with common design features including solar panels, cylinders and solar store (the first of the client’s preferred options for additional energy sources) and four possible energy options for each sample property.

Option A includes a boiler and photovoltaic panels.

Option B replaces the boiler with an air source heat pump, a gas fire to compensate for any cold weather shortfall and increased solar panel size. The architect notes that the available roof space may not accommodate the required increase in solar panel size to achieve the overall target DER for this option. In addition, air source heat pumps are the client’s third (of four) preferred options for alternative energy sources.

Option C is similar to Option B, with a more efficient gas fire.

Option D replaces the air source heat pump with a ground source heat pump and replicates Option C’s gas fire.

161 All options for each of the sample property types achieve or exceed the calculated DER score to achieve the 44% minimum CO2 emission reduction target, summarised at Table 4.9. The lowest DER for each option is highlighted, and the nearest to the target DER (the highest) is in italics (where the lower calculated result is better).

Table 4.9 Comparison of DERs for energy options

Plot 1 11 15 43 TER 11.72 12.92 13.11 14.91 Option A 11.71 12.82 12.97 14.73 Option B 11.72 12.90 13.11 14.48 Option C 11.58 12.72 13.01 14.09 Option D 11.43 12.75 12.8 13.91

Option B, the nearest to the DER for plots 1, 11 and 15, uses air source heat pumps, the client’s third (of four) preferred options for alternative energy sources. Option D, using ground source heat pumps (the client’s second preference), returns the lowest DER for plots 1, 15 and 43.

Additionally, the architect made use of property orientation to optimise solar gain on north / south facing homes, to include potential shading for south-facing windows.

The schedule provides the contractor with information for costing the range of potential solutions to inform a final decision on an energy option for Smith Lane that meets the client’s preferences as expressed in the Design Guide and budget for the project, and the contractor’s formal Board approval.

Part of the way through the Smith Lane development project (and after the case study timeframe) the contractor decided to pull out of the Smith Lane development project. The specific impact of this on analysis of Research

162 Question Two is that information on the eventual agreement on and costing of a solution, and the decisions that supported, it is not available.