Zero carbon building (ZCB) has emerged as an innovative approach to improving building energy performance and reducing building carbon emissions. However, the uptake of the ZCB approach is slow, far from the mainstream practice of building. Previous studies have devoted to analyze the technical feasibility and design issues of ZCB. Some have examined the barriers to the adoption of ZCB practices in the market, social, regulatory and/or financial aspects. However, few have explored the role of business models in the delivery of buildings towards zero carbon. The aim of this paper is thus to examine the effect of business model on ZCB, and to explore innovative business models that can stimulate the uptake of ZCB. The paper first reviews the concepts of ZCB and identifies the challenges to ZCB based on the PESTEL analytical framework. The paper then investigates the conceptual framework of business models for ZCB. Nine key elements of the business model are identified, which include offering, target customer, distribution channel, customer interfaces, resource and core competency, partner network, cost and revenue model. Evidence is collected to substantiate the arguments through case study with one recent ZCB project selected from varied contexts. The results of the case study presented an innovative business model that helps address the challenges to delivering ZCB. The research findings help to demonstrate to practitioners the business potential of ZCB and to guide how innovative business models can help accelerate the uptake of the ZCB approach.
Case Studies of Low and Zero Carbon homes
The following section illustrates a number of examples of dwellings built to the standards for low carbon retrofit and new build. These projects typically have delivered energy and CO2 performance, well in advance of what has been required by building regulations. These examples include a range of approaches adopted, and are intended to illustrate the differing of approaches that have been adopted to reducing energy and CO2 from domestic buildings.
- New Build
- Code for Sustainable homes level 5 – Parkfield, Thurlestone, Devon, UK
Figure 1 Code 5 passive social housing development -Thurlestone South Devon (SDC, 2014)
The project included a requirement to achieve CfSH level 5, meaning zero CO2 emissions from regulated emissions (heating lighting, hot water, pumps and ventilation). This also included requirements to reduce water usage to 80l per person; via rainwater harvesting, along with a range of other exemplar sustainable features. The project was for a small housing association social housing client.
The project includes 4 dwellings in the form of 2 pairs of semi- detached dwellings, each 3 bed/ 5 person. The build uses a modular timber frame system, manufactured offsite under factory conditions in Ireland. This way of building allows a rapid and efficient build process, reducing waste and enabling foundations and frame to be built simultaneously.
The aim of the project was to demonstrate the potential for exemplary sustainable housing to be delivered for affordable and social tenants in a rural location, typically with no gas grid connection. The approach adopted Passivhaus principles and specification, although did not pursue Passivhaus certification, due to the costs of some passivhaus certified components, the costs of certification and the constraints it places on the buildings orientation and layout (SDC, 2014)
|Date Completed||Spring 2014|
|Description||4, 3 bed properties (92m2)||Social housing for subsidised rent|
|Client/Developer||SDRHA – Housing Association||Small rurally focused HA|
|Construction||Timber Frame||Lightweight, offsite manufactured|
|Dwelling Emission Rate||DER ≤ -5.57 kgCO2/m2||<ZERO CO2 from heating, lighting, hot water and fans|
|Walls||0.12 W/m2k||300mm recycled cellulose newspaper insulation|
|Roof||0.11 W/m2k||400mm recycled cellulose newspaper insulation|
|Windows||0.86 W/m2k||Triple glazed passivhaus certified|
|Floor||0.10 W/m2k||Passive slab eliminates wall-floor thermal bridge|
|Heating System||Electric air in MVHR Duct||Removes need for central heating|
|Ventilation||MVHR – 95% heat recovery, Fan power 0.4W/l/s||Improve air quality and heat retention|
|Solar thermal||16 evacuated tubes||Reduced CO2 and 60-70% hot water|
|PV panels||15 panels -3.975 kW – 3204 kWh approx.||Reduced CO2 and free electricity|
|Code For Sustainable Homes||88 points from 107 – Level 5||Demonstrating exemplar sustainability across the 9 categories|
|Budget (92m2 house)||£132,500 per property||Turnkey £1,440/m2 including fees|
|Figure 2 technical specification for CfSH level 5project, Parkfield Thurlestone (SDC, 2014)|
SDC. 2014. 14-17, Parkfield, Thurlestone, Code 5, Social housing project [Online]. Sustainable Design Collective. Available: https://www.sustainabledesigncollective.co.uk/portfolio/parkfield-thurlestone/ [Accessed].