With increasing property prices, stamp duty, and simply the cost and inconvenience involved in moving houses, it’s no wonder that the majority of homeowners are choosing house extensions when faced with space issues.

House extensions are viewed as the ideal solution to increase the living space inside a home when the space within becomes too cramped for comfort. House extensions also have the wonderful benefit of increasing the value of a home when done right.

The design and style of a home extension depends largely on the space available, the additional space required, and the budget. An extension style that considers all 3 factors should be chosen to create the perfect extension.

For this reason, loft conversions are a popular style of extension as they are versatile in their designs and can add considerable living space.

To obtain the best outcome for a loft conversion, it is advisable to hire an extension specialist who can help you to avoid common mistakes people make when designing and building loft conversions.

Some of the things you should NOT do are listed below:

1. Not checking the suitability of the property

Though a loft conversion works well in most homes, an overlooked and costly planning mistake is to forget about checking if a loft conversion is suitable for your home. This mainly involves confirming that a head height of 2.3m is available in the loft space as that is the minimum required for a standard loft conversion.

2. Not complying with and adhering to legal guidelines

By legal guidelines, we mean the requisite permissions and approvals that need to be obtained before starting work on the loft conversion.

Many loft conversions do not require planning permission as they fall under permitted developments, but never assume the same applies for you. It is best to check with the local council for any permissions and approvals that need to be secured before commencing the build. This is especially important if your property is listed in a conservation area.

Building regulations approval must also be obtained to ensure that the loft conversion complies with building guidelines and standards.

Another important legal requirement is the Party Wall Agreement. This is particularly crucial if your property is a semi-detached or terraced home. The shared wall means that neighbours have a right to dispute the extension.

For this reason, clearly communicating your plans with the neighbours and obtaining a party wall agreement can save you a lot of expense and inconvenience in the long run.

3. Not considering the layout

The layout and interior design of the loft must not be left for later approval. This is because it can impact the build of the conversion in small and significant ways.

Some important considerations that can affect the overall design and floorplan include the placement of switches, sockets, and lighting.

The roof type that you select can also heavily impact the final loft conversion design as does the positioning of doors and windows.

All of these factors affect the space and natural light within the room, and must be thought out with respect to how the room is eventually going to be used.

4. Incorrectly positioning the staircase

One of the most important aspects of designing a loft conversion is the positioning of the staircase. This is due to the headroom required on the landing.

Generally, a headroom of 1.9m at the centre of a stair is needed. For this reason, the staircase landing is usually positioned in line with the ridge of the roof.

However, this can encroach upon the room design and may be awkwardly placed next to the bed or directly in front of the bathroom door. So, alternatives such as including a dormer window to achieve the necessary headroom must be considered.

Staircase placement and design are also crucial factors for building inspectors, and as such, must be thoughtfully positioned to ensure you obtain the requisite safety approvals.

5. Incorrectly installing heating/ cooling systems

With lofts being directly under the roof of a house, they are most susceptible to outside temperature changes and should therefore be properly heated or cooled as per seasonal requirements.

The heating of a loft room can easily be connected to the central heating system but it may need to be upgraded to support the extra load.

One additional unit is usually adequate for providing heating/ cooling to a loft, but its size and placement must be decided after considering the interior layout of the loft room. Additional simple measures such as the installation of well-placed windows and shutters can have a considerable impact on the heating/ cooling requirements within the loft.

6. Forgetting about storage space

With the loft space being used as a storage area, converting it into a useful and functional room can add incredible living space within your home. But this often leads homeowners to overlook the need for additional storage space to store the items normally kept here.

Decluttering, organising, and installing in-built shelves in ill-used spaces or awkward corners, can help homeowners overcome these storage concerns.

7. Hiring the wrong contractor

As with any project, the right advice and expertise can go a long way in easing issues and concerns.

For a loft conversion to be the extension you envisioned, it is therefore advisable to hire a loft extension specialist, not just an everyday builder. Loft extension specialists will have the necessary skill and expertise to design and build the ideal loft conversion for your property.

It is important to remember that the most expensive does not always equate to the best. So, look around. Get quotations and recommendations. And choose the right fit for you.

Chances are you will be spending a lot of time with your contractor. Finding someone you can easily communicate with, and who is open and flexible to your ideas and opinions, can help make the process more comfortable, smoother and easier.


Loft conversions are a relatively simple and cost-friendly solution to increasing the floor space within your home and may increase the value of a property by 20%.

But to get the maximum value from your investment, it is crucial to get the best extension builders who specialise in loft conversions. They can not only optimise the space, oversee the process, and give the best advice, but can also help you to avoid the many common mistakes and blunders during the design and build process that could prove to be costly in the long run.

If you are looking for the ultimate loft conversion specialists to help you construct the perfect loft conversion, look no further than Good Design and Build!

We specialise in designing and creating bespoke conversions and extensions that add incredible space and value to your home, making your extension dreams an absolute reality.

Author: Amol

Amol is an architectural designer and has worked on hundreds of residential projects in London since 2008.Having done his M.Arch from the Glasgow School of Arts he gained valuable experience in London working in the construction industry managing high-end residential projects, before founding Good Design and Build in 2015.You will meet him for initial consultation and work closely with him during all stages of your project