St Modwen SBE0079

Written evidence submitted by St. Modwen


We operate across three dedicated business units: St. Modwen Homes, St. Modwen Logistics, and Strategic Land & Regeneration, all of which are aligned to structural growth trends and contribute towards our purpose of ‘Changing Places. Creating Better Futures’.

A constituent of the FTSE 250, we employ over 600 people and are active across England and South Wales, with a portfolio totalling £1.41bn.

We believe that purpose and profit are inextricably linked and know that our financial performance must be delivered in tandem with having a meaningful, positive impact on society and the environment. We have chosen six Responsible Business ambitions to deliver this, including:

We are submitting evidence to the Environmental Audit Committee’s consultation to contribute insights from our experiences in implementing sustainability improvements and highlight where further action is needed from Government and regulators.


  1. To what extent have the Climate Change Committee’s recommendations on decarbonising the structural fabric of new homes been met?

Across the construction industry there has been limited progress since the Climate Change Committee (CCC) made its recommendations. However, there has been a recent increase in the use of timber frames which will help decarbonise the structural fabrics of new homes compared to traditional builds that used block or brickwork. In addition, the recent consultation and publication of Part L of the new building regulations will help deliver the reduction in carbon emissions, albeit this is focussed on energy-in-use rather than the reduction of embodied carbon within building materials.


  1. How can materials be employed to reduce the carbon impact of new buildings, including efficient heating and cooling, and which materials are most effective at reducing embodied carbon?

The reduction of the carbon impact of new buildings, in both housing and commercial property, starts from the design of the building through to its operation.

The use of recycled and reclaimed materials can reduce the carbon footprint of buildings. This reduction is magnified when recycled and reclaimed materials are sourced local to a site because it avoids emissions from transport movements and waste disposal.

Wherever possible, St. Modwen recycles materials from site and reuses them in landscaped areas and sub-base preparation. We aim to source recycled aggregates and soils locally.

Installing low water flow showers and WCs reduces the use of water and achieves an increased water efficiency of 12% compared to the regulatory benchmark. A secondary consequence of increased water efficiency is reduced carbon emissions as less water is needed from water providers, reducing the energy expended on processing.

The provision of a high degree of insulation in walls, roofs, and floors, has a beneficial effect on reducing the energy needs for heating buildings.

St. Modwen’s warehouses utilise a range of features to reduce the carbon impact of the building:


  1. What role can nature-based materials play in achieving the Government’s net zero ambition?

The use of nature-based materials in the Built Environment can help achieve the Government’s net zero ambition. In particular, timber - either through a conventional timber frame, cross-laminated timber (CLT), glue-laminated timber, or other forms of timber construction - has a significant role to play in replacing materials such as steel.

It will not be possible to substantially reduce the embodied carbon of new homes without a significant switch to timber as the primary structure. Encouragingly, for low-rise housing, the technologies already exist. However, these technologies are generally considered to be more expensive and less flexible than traditional brick and block construction meaning they are unlikely to become the status quo without regulation targeted at embodied carbon reduction rather than just carbon in use.

St. Modwen is currently piloting two timber frame Passivhaus homes at Copthorne in West Sussex, and we are in the early stages of planning a 40-unit timber frame site at our Hilton Valley development in Derbyshire.

There is also scope for increased use of nature-based materials as alternative insulation options. These include sheep’s wool, straw, and recycled paper, but more research is needed into the performance of these products and to assure their thermal and fire-safety performance.

Hemcrete – a building material comprised of a mixture of hemp and lime that can be used to make walls and is carbon negative – has been explored as a possible alternative to current industry practices. In the future, there will be a need for innovation in similar materials.


  1. What role can the planning system, permitted development and building regulations play in delivering a sustainable built environment? How can these policies incentivise developers to use low carbon materials and sustainable design?

As outlined in our response to the Government’s “Planning for the Future” white paper, St. Modwen supports any simplification of the planning process.

Sustainable development tests

The proposed abolition of sustainability appraisals is welcomed as they have become lengthy, convoluted documents. A set of sustainable development tests that the authority is required to meet could shape how standard local plans should be produced and assessed is supported if implemented properly. The aim must be to improve transparency for plan-makers and the development industry over the rules associated with making and reviewing plans.

However, we would like to understand how the sustainable development test would work. Local authorities should set out a clear vision and, from this, their spatial strategy. In our view, this is important and will potentially differ considerably between authorities based upon their geography, demographics and political priorities.

A sustainable development test based upon the authority’s vision and strategy is important to ensure that proposed allocations are aligned. However, this also needs to align at a national level, and an integrated approach taken to ensure a level playing field and whole life carbon is considered for developments.

Local targets conflicting with Building Regulations

Currently, local targets that require a minimum percentage of energy from renewable sources can actually conflict with Building Regulations. Targets that require the use of renewable energy, but do not require an uplift in the overall carbon performance of the building, effectively encourage developers to recover the money spent on renewables by using cheaper building fabric. 

Most industry figures recognise that a fabric-first approach is more sustainable, but current targets incentivise the opposite approach. A consistent national approach, via Building Regulations, which encourages developers to invest in research and development towards a higher standard, is needed. 

Our analysis has shown that compliance with the consultation drafts of Approved Document L 2021 can be achieved, without any improvement in current building fabric, just by adding photovoltaic (PV) technology. The consultation did mention the possibility of requiring a 15% improvement in building fabric – and given the above analysis, it is our view that this should be adopted.  

Opportunities for improvements

There remains a disconnect between the aspiration to achieve sustainability improvements and current regulations which are entrenched in traditional forms of operation. There is currently limited scope for innovation through building and infrastructure regulations.

One example of this disconnect is evident in Part L of Building Regulations, which covers the energy efficiency requirements of buildings. It has not been updated since 2013 to reflect improved sustainability standards. The reform of Part L is an obvious opportunity to incentivise developers to use low carbon materials and sustainable design.

Another opportunity to improve regulation is in relation to local authorities’ restriction of the reuse of recycled and sustainable low carbon alternatives to tarmac and aggregates. As an example, highway authorities insist on fresh-quarried stone rather than recycled material. However, there is no reason that appropriately graded recycled material should be viewed as inferior.

Many materials specified and used in construction are set out within standards that are defined as acceptable to building control standards and other construction standards such as infrastructure. The standards specified are limited and often do not permit innovative or recycled materials content. All Government departments should be looking at ways to encourage low carbon materials on both buildings and infrastructure projects.


  1. What methods account for embodied carbon in buildings and how can this be consistently applied across the sector?

In relation to embodied carbon, whole life carbon assessments should be used to fully evaluate and understand the impacts from material choices. In the Built Environment, the focus needs to be on bricks, blocks, tiles, steel, concrete, and plaster, because these materials have the highest levels of embodied carbon.

A transition to low carbon concrete should be part of the solution as there are realistically no alternatives for below ground structures. Additionally, clay-fired bricks should eventually be replaced by low carbon concrete bricks, wet skim plaster should be replaced by tape-and-joint plaster, and metal studwork by the use of timber.


  1. Should the embodied carbon impact of alternative building materials take into account the carbon cost of manufacture and delivery to site, enabling customers to assess the relative impact of imported versus domestically sourced materials?

As part of the drive to tackle embodied carbon, there is a clear need to identify all areas of carbon impact, including those associated with alternative building materials. This should form part of a wider whole life carbon assessment of materials and their carbon cycles across the supply chain.

In doing so, a more suitable picture of the wider carbon impact will be formed, from the initial stage of material gathering to the endpoint of material recycling. In turn, this will help pinpoint the most carbon intensive stages in the building cycle and help inform action.  


  1. How well is green infrastructure being incorporated into building design and developments to achieve climate resilience and other benefits?

As a housebuilder with an ambition to achieve operational net zero by 2025, and full net zero by 2040, sustainable construction is a primary focus of our business.


From the procurement of low carbon, highly recyclable building materials, to the design of modern and industry-leading homes with superior envelope characteristics including high levels of insulation and airtightness, low energy design principles are embedded at every stage.

There should also be consideration of smart micro-grid solutions, coordinating photovoltaic (PV) technology, batteries, and electrical heating systems, that help balance the electricity demand across a development.

Over the course of a development’s lifecycle, we have measures in place that are designed to reduce scope 1, 2, and 3 carbon emissions. In addition, St. Modwen developments include a number of additional green infrastructure elements:



  1. How should we take into account the use of materials to minimise carbon footprint, such as use of water harvesting from the roof, grey water circulation, porous surfaces for hardstanding, energy generation systems such as solar panels?

We are committed to exploring all kinds of innovation intended to reduce the carbon footprint of development. As a rule, it is important to consider whole-life carbon assessments and move away from a focus on turn-key assessments. This includes a focus on all aspects of building design rather than just operational impacts.

Across St. Modwen properties, a range of materials designed specially to reduce the carbon footprint are used:


  1. How should re-use and refurbishment of buildings be balanced with new developments?

It is important to acknowledge that re-use and refurbishment offer many sustainable opportunities, but the industry must fully consider the quality of the existing materials, their re-purposing potential and design schemes which deliver the critical combination of place and sustainability.

There is a unique opportunity for volumetric modular buildings in achieving this through their portable nature and re-use potential. 

At the concept stage, material management plans and re-use opportunities must be identified from the outset of a scheme.

For example, there is an important opportunity in the path to low carbon heating where buildings reliant on gas infrastructure can transition to low-carbon heating, supported by the necessary grants or incentives from Government. In the Ten Point Plan for a Green Industrial Revolution, the Prime Minister outlined the ambition to install 600,000 heat pumps every year by 2028 and this is a welcome step in the heat transition.


  1. What can the Government do to incentivise more repair, maintenance and retrofit of existing buildings?

The Government should consider sustainable solutions for all building types that require retrofitting to ensure alignment with net zero carbon ambitions. As part of this, whole-life carbon assessments are essential in understanding the various carbon impacts and savings that can be achieved at any particular stage by different interventions.

In line with existing commitments to tackling fuel poverty, and as part of a more inclusive transition, there should also be consideration for special incentives that aid households in fuel poverty as a result of poor-quality builds and inefficient heating systems.

May 2021