igloo Regeneration Ltd                            SBE0136

 

Written evidence from igloo Regeneration Ltd

 

igloo Regeneration Mini Case Study

The Supply Chain for Delivery of Homes to the Future Home Standard with Low Embodied Carbon

 

Summary

igloo is one of the UK’s leading responsible real estate businesses, working with investors, communities, local authorities and landowners who share our Purpose – to create and deliver Impact-driven projects for People, Place and Planet. As a Certified Benefit Corporation (B-Corp), igloo’s purpose is legally enshrined in its company Articles.

 

igloo has a proven development track record. Over 20 years we have been trusted to deliver regeneration development projects for major UK financial institutions (including PfP Capital, Aviva and Nationwide Building Society), public-sector authorities (including Homes England, the GLA, Nottingham and Newcastle City Councils), and community groups (including Leathermarket CBS and Styles House TMO). igloo is an active member of UKGBC and is working with the UKGBC internal team as a participant in the Whole Life Carbon Roadmap Task Group for new housing.

 

This is a case study based upon the first phase of a major local authority led regeneration project with strong sustainability ambitions and carbon reduction plan in a medium sized regional city. The case study highlights current constraints within the UK construction industry in delivery of new-build homes, at scale, that meet the energy efficiency requirements of the Future Home Standard proposals alongside an ambitious target for reduction of carbon emissions home fabric construction.

 

Summary findings against the specific Terms of Reference for the Environmental Audit Committee Enquiry:-

 

 

Forward thinking clients, in this case a local authority, can take the lead in setting out ambitious proposals for decarbonisation, both operational and embodied, of the structural fabric of new homes. The construction industry and its product supply chains, is not yet able to deliver against these without bespoke design changes to MMC systems which add cost, delivery and quality assurance risks.

 

In this case, the 132 homes in the first phase have been designed to achieve the Future Homes Standard using the passivhaus methodology with some home targeted to receive full passivhaus certification. If delivered to passvihaus standard it would be largest passivhaus project in the UK. However, all 12 pre-qualified national and regional contractors on the first stage tender panel have declined to tender or not responded.

 


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Construction materials are available which will reduce operational and embodied emissions of individual construction elements. These are not yet incorporated into established MMC technologies at scale and into construction supply chains. Funding for BRE BBA certification and home warranty provider approvals is a potential constraint for manufacturers and suppliers of innovative low embodied carbon materials

 

 

There are nature-based materials available, for example structural timber and hemp or cellulose insulation, but these in combination are not available within MCC system supply chains. The main constraint here is the lack BBA Certification for the materials, funding for the certification process, and the consequent inability to secure home warranty provider cover for a structural fabric using these materials.

 

 

The planning system and building regulations need to set requirements for measurement of embodied carbon using an established modelling methodology (for example the RICS LCA Methodology - https://www.rics.org/uk/upholding-professional-standards/sector- standards/building-surveying/whole-life-carbon-assessment-for-the-built-environment/ ) and a path for reduction of embodied carbon within the structural fabric of homes.

Alongside this, there needs to be a requirement for construction material manufacturers to produce Environmental Product Declarations (EPD) that declare the embodied carbon within the product. Currently this is voluntary and not required for BRE BBA Certification of the material.

 

 

See above.

 

 

These factors are considered in the RICS Methodology and Environmental Product Declarations.

 

The Project

The case study is based upon the design and procurement of the first phase of a new urban quarter being created by client local authority on a superb riverside site in the heart of a medium sized regional city. The strategy to deliver this transformational change is enshrined in a masterplan, unveiled in October 2020, that sets out to create 1,000 homes for a community of 2,500 people, and 1 million square feet of offices and workspace for 8,000 – 10,000 quality jobs. Beautiful parks and public spaces will create the setting for a new community and a new urban quarter. The local authority client is determined that the site’s remarkable landscape setting and its rich cultural


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heritage should be reflected in outstanding urban design and architecture, Smart City infrastructure, and a sustainable development model that will contribute to the city’s carbon-neutral ambition.

 

Phase one of the Project

Phase one is the first of the four residential neighbourhoods proposed in the masterplan and the first phase to be delivered. There will be 132 homes in the neighbourhood, which will also be the site a future housing exhibition. The site’s proximity to the central business district of the city lends itself to high density city living, which will be achieved by assembling houses in mews and courtyard forms inspired by historic precedents. Helping the city move towards a sustainable future, the homes at have been designed around energy and carbon reduction, using modern methods of construction (MMC) and a range of low carbon technologies and renewable energy (See the images at Appendix A)

 

Sustainability Strategy for New Neighbourhood - The Journey to Net Zero

 

60% carbon saving compared with current benchmarks. The overall embodied carbon target was an average of 450 kg of CO2 equivalent embodied emissions per square metre of gross internal floor area. A typical 3-bed home of 100 sq. metres would therefore have 45 tonnes of CO2 of embodied carbon emissions at completion.

 

Preliminary Design Proposals Agreed with the Client

 

Energy Strategy: Homes will be designed to reduce their energy demand and consumption, will use air source heat pumps to provide low carbon heat and maximise the use of renewable energy.

 

Whole Life Carbon Strategy: The development aims to reduce whole life carbon impacts minimising both embodied and operational carbon.

 

Transport Strategy: Active travel solutions will be prioritised along with provision for low carbon mobility.

 

Materials Strategy: By embracing circular economy principles, the scheme will minimise consumption of virgin materials, specify the use of low carbon and renewable materials as well as prioritise locally sourced options.

 

Waste Strategy: Adoption of lean design methods to reduce waste throughout the entire lifecycle of our development. Put in place strategies to reduce operational waste.

 

Green Infrastructure Strategy: The development will provide new green infrastructure and will achieve biodiversity net gain.

 

Water Strategy: Water efficiency will be maximised. Additionally, the proposed drainage design mitigates flooding risk and ensures appropriate management of surface water and foul water.


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Climate Resilience Strategy: The development proposals also aim to increase resilience to adverse climate change, by designing in response to the local microclimate and for climate change.

 

The Structural Fabric for the New Homes

The Committee on Climate Change (CCC) recommends that new homes deliver ultra-high levels of energy efficiency, with a space heating demand of 15-20 kWh/m2/yr by 2025 at the latest. They have also recommended that from 2025 at the latest, no new homes should be connected to the gas grid.

 

The Future Homes Standard (FHS) is the proposed regulatory framework for delivery of the CCC recommend target for energy efficiency. This will set a 75-80% carbon reduction target against current requirements (Part L 2013), with Part L 2021 acting as a steppingstone to this, with a 20-31% carbon reduction target.

 

Fabric Energy Efficiency

A fabric first approach is at the heart of the sustainability proposal for the development and a range of passive design and energy efficiency measures have been designed into the project to reduce energy use. High fabric insulation levels is targeted, as well as high performance glazing with optimised glazing ratios to balance heat losses, heat gains and daylight ingress. The space heating demand targeted is between 20-15 kWh/m2/yr in line with recommendations from the Committee on Climate Change and the passivhaus criteria. Part of the scheme is to go through full passivhaus standard certification with the rest of the development following passivhaus methodologies for fabric efficiency and to minimise the performance gap between modelled carbon and energy and actual performance of the homes.

 

Whole Life Carbon

In addition to targeting reductions in regulated carbon emissions and energy use, as measured by Building Regulations, the scheme is targeting reduced carbon emissions from other sources. The most significant other source is the upfront embodied carbon associated with construction materials and the construction process.

 

A whole life-cycle carbon assessment has been undertaken to support lower carbon design decisions. The assessment has been undertaken in accordance with the RICS professional Statement for WLC assessment. There are no specific planning or regulatory deliverables for embodied carbon and the project has been assessed against industry best practice as set out in the RIBA 2030 Climate Challenge (see below).

 

RIBA 2030 Climate Challenge target metrics for domestic buildings (Source - RIBA Climate 2030 Targets, RIBA)

 

RIBA Sustainable Outcome Metrics

Current Benchmarks

 

2020 Targets

 

2025 Targets

 

2030 Targets

 

Notes

Operational Energy

kWh/m2/y

146 kWh/m2 /y (Ofgem benchmark)

< 105 kWh/m2/y

< 70 kWh/m2/y

< 0 to 35 kWh/m2/y

UKGBC Net Zero Framework

1.                  Fabric First

2. Efficient services, and low- carbon heat

3. Maximise onsite renewables

4. Minimum offsetting using UK schemes (CCC)

Embodied Carbon

kgCO2e/m2

1000 kgCO2e/m2 (M4i benchmark)

< 600 kgCO2e/m2

< 450 kgCO2e/m2

< 300 kgCO2e/m2

RICS Whole Life Carbon (A-C)

1.                  Whole Life Carbon Analysis

2. Using circular economy Strategies

3. Minimum offsetting using UK schemes (CCC)


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The RIBA guidance forms the basis for a wider industry approach to achieving net zero carbon in new build construction and sets out targets for the total energy of both the upfront embodied carbon as well as the in-use (operational) carbon.

 

Fabric Design to achieve the Target Reduction in Embodied Carbon

The baseline embodied carbon assessment assuming a ‘business as usual’ specification of the fabric envelope identified the envelope as ‘over-budget’ for embodied carbon. There is a requirement to make a circa 50% saving of the embodied carbon in the structural fabric to meet the aspirational target of RIBA 2025 – 450kgCO2 per sq. metre of gross internal floor area.

 

An offsite manufactured timber structural insulated panel (SIP) is the preferred construction technology solution for the superstructure of all the townhouse homes in the scheme. The reduced embodied carbon for this element provides some headroom for the higher embodied carbon levels of a robust external envelope to the homes (brick or hung slate) that is the preference of the planning authority. However, some of the carbon reduction benefit of a timber SIP structure is lost if high embodied carbon oil-based polymer insulation is used within the SIP in deliver the level of fabric efficiency required to meet the Future Home Standard. To minimise the embodied carbon of the structural fabric a low embodied carbon insulation material within the SIP is required. Use of natural materials such as cellulose or hemp has the lowest carbon impact in this respect (see below).

 


*Oil-based Polymer insulation.


igloo Regeneration Ltd                            SBE0136

 

At a project level, with the amount of fabric insulation required to meet the Future Home Standard switching to a non-oil polymer-based insulation reduces embodied carbon in the structural fabric by circa 12%.

Current Delivery Constraints Procurement

A panel of 12 regional and national contractors had initially been pre-qualified for the project. At present there are no contractors willing to tender for the project (see table below), although positive discussions are now underway with some of the panel based upon an alternative approach to procurement. Delivery risks in meeting the Future Home Standard through the passivhaus methodology and the perceived “specialist elements” involved in delivery to the Future Homes Standard with a low embodied carbon fabric, have been raised explicitly be some of the contractors. In addition, there are indications that the contractors generally have a programme of, and / or tender opportunities for, “easier”, less risky projects.

 

Type of Contractor – Regional / National

 

Status

 

Notes

Regional

Declined

 

Regional

No Activity

Declined to comment as to why they were not interested.

 

National

 

Opted Out

Had already committed to a quota of works and the start on site date didn’t align with their resources.

 

 

Regional

 

 

Declined

Commented that they did not have the skills to undertake such a large Passivhaus standard project. They were concerned they would not be able to deliver the standards.

National

No Activity

Declined

 

Regional

 

No Activity

Did not confirm or decline so currently none the wiser but still a possibility.

 

 

Regional

 

 

Declined

Confirmed the project had specialist elements and not their ‘bread and butter’. They did not have sufficient resource to undertake.

 

 

Regional

 

 

Opted Out

Did not have sufficient resource to tender a single stage D&B. They would be able to take part in a two stage tender.

National

Declined

 

National

No Activity

 

Regional

Declined

 


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National

 

 

No Activity

Preferred to use their direct award framework rather than tender single stage D&B. Would perhaps undertake a two stage tender (but later on refused to tender two stage).

 

Supply chain for the Structural Fabric

Research and enquiries with MCC providers using timber SIP construction technology has shown that at present delivery of a Future Home Standard compliant fabric, with low embodied carbon insulation, is not possible at scale without either

 

 

The former adds significant costs at the manufacturing stage and is not viable without large volume orders. The latter reduces some of the benefits of using an MMC approach to construction by introducing additional on-site works, increasing construction programme length and adding to weather delay risks. Bespoke on site works also increase quality assurance risks and client quality monitoring costs.

 

The above issues have also been highlighted by architects and other expert consultants within the UKGBC Whole Life Carbon Task Group for new-build domestic. Without regulatory or planning requirements the potential trajectory for the MMC sector will be towards a product offer that meets the Future Homes Standard whilst locking in embodied carbon emissions into the material supply chain. As the volume house builder sector bring forward new standard house types to deliver homes that meet the Future Home Standard their supply chains could be locking in embodied carbon emissions at levels at sector level.

 

Conclusions

This is a new-build residential project of reasonable immediate scale and, with the further phases, it is significant business opportunity for the construction sector at both a regional and national level. For this reason, the lack of immediate appetite from the market is both surprising and disappointing. The project has some design complexities but only at a level that will need to be faced when the Future Homes Standard becomes a regulatory requirement.

 

Offsite manufacture of building elements and modern methods of construction will be an essential and growing segment of overall new build housing delivery. MMC will drive the technical solutions and quality enhancements that are required in the sector to meet the Future Homes Standard, reduce delivery times, minimising construction waste, and eliminate the current energy efficiency performance gap between modelled and actual performance. Current scalable MMC solutions do not have material supply chains that can drive down embodied carbon emissions in the manufacturing process to the level required to deliver a net zero new build housing sector. There needs to be regulatory pressure to ensure that increased take up of MMC by the volume house building sector does not lock embodied carbon emissions into new supply chains that will be created by this process.

 

May 2021

 

Appendix A – scheme images (copyright igloo Regeneration Ltd)


 

 

igloo Regeneration Mini Case Study - Project Images