Heritage Works for Housing: Managing Change

It is likely that MEP upgrades will be required. This can also improve the building's operational carbon and running costs. It is best practice to minimise intervention in the building by making use of existing openings and risers where possible, or routing the MEP through any new build elements. These also need to include practical considerations for the end users, such as location of radiators or ventilation extract locations.

If there is a desire or need to meet certain sustainability targets, then this will need to be balanced against the potential heritage harm of interventions.

This is a particular consideration for investors who may have specific mandatory energy targets. When reviewing these targets, it is important to take a whole building approach to deliver maximum benefits.

Embodied and operational carbon should be understood together to ensure decisions are being made that will have the maximum effect with the least impact on the special interest of the building. For example the return on carbon savings may not be justified by fabric interventions (e.g. roof, floor, walls, windows) due to their high embodied carbon, including construction impacts, and therefore higher carbon savings may be achieved through a focus on operational carbon, noting the target for "zero carbon by 2050".

Historic England's guidance on Energy Efficiency and Retrofit in Historic Buildings sets out further advice on specific interventions.

The performance of windows affects both the energy efficiency of a building and the ventilation strategy.

As part of a holistic review of the building’s energy performance, options that may be considered include the use of secondary glazing or replacement of the glass within the original window frames. Given the prominence of windows on the appearance of a building, these are often areas of high significance.

Where historic windows, whether original or later insertions, make a positive contribution to the significance of a listed building they should be retained and repaired where possible.

Historic England’s Guidance Modifying Historic Windows as Part of Retrofitting Energy-Saving Measures sets out further advice on specific interventions.

It is important that the homes are places where people will want to live. It is necessary to consider how the building will be ventilated in the summer and what other overheating mitigation may be required.

There may be a need to mitigate sound transfer either between units or uses – or from the outside. This acoustic assessment will need to balance necessary acoustic attenuation and the concealing of areas of significance within the building. 

Some historic buildings may have non-typical floor-to-ceiling heights. If floor-to-ceiling heights are too low, significant intervention may be required such as the removal of every other floor. If floor-to-ceiling heights are too high, then the building may be less energy efficient. However, high floor-to-ceiling heights provide opportunity for the introduction of mezzanines and duplex apartments.

How the building is sub-divided into multiple homes needs to be carefully considered. This should balance a consideration of the original planform and where the special interest of the building lies alongside market expectation, regulations, policy and guidance.

Unless there is a robust justification, all residential developments are expected to comply with Nationally Described Space Standards, including those created through PD Rights.

Particularly where a building is sub-divided there may be a need for different or new forms of circulation space within the building and potentially new entrances and fire exits and staircases. It may also be that new openings are required to introduce lifts, or existing lifts are required to be modernised, potentially with new car lift systems within existing lift shafts.

Guidance on balancing the importance of creating accessible places for all and increasing access to the building, with potential impacts on the significance of the building is provided by Historic England in Improving Access to Historic Buildings and Landscapes.

There can be an expectation or requirement from planning policy for on-site car provision (including Blue Badge parking). Agreeing the proportion of car parking and its location is important. This is particularly the case where there may be limited surrounding developable land, extensive structural intervention required, or new structures required. In addition, it may be that the building is rurally located, in which case consideration will need to be given to how the proposals will encourage sustainable travel.

Proposals will need to provide adequate bin stores and servicing arrangements, which can be trickier to accommodate within a historic building.

Where planning applications for a residential use do not comply with affordable housing policy, they will be required to submit a viability statement as required under local planning policy and the NPPF. Viability can be constrained on heritage projects and therefore it is often demonstrated that it is not viable to include affordable housing. Additionally, there may be complexities around a Registered Provider occupying the building due to the potentially unusual layouts and long-term maintenance costs. Conversely, through working collaboratively with Registered Providers there are circumstances where grant funding may enable challenging historic buildings to be restored and secure their long-term viable use as affordable housing.

There can be a tension between fire safety and heritage matters. These may be fire break locations, treatment to existing fabric, and door upgrades. It is important to consider how this can be addressed at an early stage and understand any bespoke solutions that may be required.

Can be less ornate but are often examples of innovation through construction and materiality (e.g. asbestos), which can result in poor energy performance. They therefore may require more investigation and bespoke technical solutions.

The historic building will likely require some areas of repair, of lesser or greater degree depending on the condition of the building. Like-for-like repairs should be considered in the first instance and do not typically require consent.

The historic building will likely require some areas of repair, of lesser or greater degree depending on the condition of the building. Like-for-like repairs should be considered in the first instance and do not typically require consent.

Historic buildings often require sensitive cleaning of the façade and interiors which may need to be agreed with the local planning authority.

Generally archaeology is required only for below ground works. For reuse of a historic building this may also include where lift pits are required.

Where there is a new build element it is recommended an early archaeological desktop study is undertaken to assess the likelihood of below ground heritage.

It is typical that archaeology works are a recording exercise, often involving trial trenching. Allowing for these investigations and factoring these into the programme can create efficiencies whilst other activities may be occurring on the site, such as an early works.

Proposals will need to be cognisant of the flood zone the building and land is located in. There can be restrictions on uses, including residential at ground floor level. The impact of flood risk elsewhere may also need to be considered, especially for any new build element.