Change of use projects: Where schemes commonly go wrong

With demand for new housing continuing to grow and many commercial buildings remaining underused, change of use projects have become an increasingly attractive option for developers. Office-to-residential conversions, continue to offer opportunities to bring vacant buildings back into use and unlock the potential of existing sites.

While these schemes can appear more straightforward than new-build developments, they often present their own challenges. Existing buildings come with constraints that aren't always obvious at the outset, and overlooking them can lead to delays, unexpected costs and design changes later in the project.

Some of the most common issues we see?

Assuming planning is the biggest hurdle

Planning permission or permitted development rights are often the first consideration for a change of use project, but they're only part of the picture.

Even where a change of use is acceptable in planning terms, there may still be a range of technical assessments required to support the application or satisfy Building Regulations. Identifying these requirements early helps avoid unexpected issues as the project progresses.

Underestimating the existing building

Unlike a new-build development, an existing building brings with it inherited constraints.

Older buildings may have limited insulation, ageing building services, restricted ceiling heights or layouts that make compliance with current standards more challenging. Features that work well for office accommodation don't always translate into comfortable, energy-efficient homes.

This is something we're grappling with directly at the moment, across a number of office-to-residential conversions we're currently working on. A big part of the early work is establishing whether a building is genuinely suitable for conversion at all, and that means really getting to know the existing structure and fabric, and understanding how it will need to work alongside fire protection requirements for residential use, which are more stringent to what's typically required for commercial buildings.

A thorough understanding of the existing building is essential before design work progresses too far.

It's also why we always build in more site visits than we might for a new-build project, particularly at the early feasibility and design stages. Fabric condition, structural grain, and fire compartmentation aren't things you can fully assess from drawings or a desktop survey; you need to be in the building.

Leaving technical assessments too late

One of the most common causes of delay is treating technical assessments as something to commission once the design has been completed.

In reality, many assessments influence the design itself. Daylight and sunlight, overheating risk, noise, air quality, ventilation, energy performance and ecology can all affect the viability of a scheme and may require changes to layouts, glazing, ventilation strategies or external spaces.

Engaging specialists early allows potential issues to be identified before they become costly redesigns.

Overlooking overheating risk

Many office buildings were never designed to provide comfortable residential accommodation throughout the year.

Large areas of glazing, limited opportunities for natural ventilation and urban locations can all contribute to overheating. As homes are occupied differently to offices, designs that performed adequately in their previous use may no longer be suitable once converted.

Assessing overheating risk early allows passive design measures to be considered before more complex solutions become necessary.

Forgetting the impact of Building Regulations

Meeting current Building Regulations can be one of the biggest challenges for change of use projects.

Requirements relating to energy efficiency, ventilation, fire safety, acoustics and overheating may all require upgrades to the existing building fabric or services. These interventions can have implications for cost, programme and the overall design.

Understanding these requirements from the outset helps project teams make informed decisions and avoid unexpected revisions later in the process.

Fire safety is a good example: residential compartmentation and means of escape requirements are rarely compatible with an office's existing structure and layout without significant intervention, which is exactly why establishing this early is so important.

Taking a joined-up approach

Successful change of use projects are rarely achieved by addressing each discipline in isolation.

Architects, planning consultants, environmental specialists and engineers all contribute to creating schemes that are not only policy compliant but also deliver high-quality places to live. Coordinating these disciplines from the earliest stages helps identify risks, resolve potential conflicts and streamline the planning and design process.

Looking ahead

As pressure to deliver new homes continues and sustainability remains a key consideration, the reuse of existing buildings is likely to play an increasingly important role in development.

Change of use projects can offer significant opportunities, but they also require careful planning and a clear understanding of the technical challenges that come with adapting an existing building. Identifying potential constraints early, rather than responding to them later, is often the difference between a straightforward conversion and a costly redesign.

With the right information at the right stage, project teams are better placed to deliver schemes that are compliant, efficient and fit for long-term occupation.

Talk to our team about the feasibility of your change of use project.