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"Graham maximised the potential of our loft conversion. We didn't really know anything about the permission we'd need, but he guided us through it and then even sourced a trusted builder to do the work. We had friends who had been let down by their builder numerous times, so we were very pleased to avoid this."


In this section I have written some brief guides to hopefully help with some of the most common questions that get asked by clients ... 

Cornerless extension, bifolding doors, outside in. Graham O'Connor Architecture, Guildford
Structural Glass extension, Glass room, exposed brick, interior architect. Graham O'Connor Architecture, Guildford, Surrey


This is the most common question for people altering their property

In this article I will discuss this in outline, to try and give you an understanding of the essential information.

There are 2 main types of approval. The first is permitted development

and the second is planning permission.


Permitted Development
Put simply, permitted development is a set of rules and limitations for changes to your property. They are designed to have clear limits and so they can often be fairly straightforward, when armed with the right information. However, the limits can become more complex and 
you can then find yourself in a greyer area or need an understanding of exclusions, etc. This is where someone like me can help you.

Will I Need Planning Permission?

Structural glass extension, natural larch cladding, interior architect. Graham O'Connor Architecture, Guildford, Surrey

Very broadly, the main areas permitted development covers are:

  • The proportionate scale of your project to your existing property, often including any existing extensions.

  • The materials used (often in keeping or complimenting existing materials).

  • The property's surroundings – proximity to neighbors, conservation areas, etc.

  • The limits/edges of the project. Examples include that single-story extensions can often have a bigger footprint than two-story extensions under permitted development, that changes to the front of your house are far more restricted, that you must consider existing roof lines and boundaries, etc.

  • The use of the new space. For example, a suitable outbuilding can be an office or gym, but any 'habitable space' usually needs planning permission.


It is important to note that a permitted development must still conform to building regulations, and it is always recommended that a 'certificate of lawfulness' is applied for in advance. This still involves a submission to the local authority, but has fewer factors involved than a planning application- you are usually waiting for your application to reach the top of the pile. The certificate of lawfulness proves the property has the correct approvals, and is important when selling the property too.

All up-to-date information on permitted development is available on the government's website.


Planning Permission

Anything that does not fall within the limits of permitted development will need planning permission from your local authority. This is a submission of all of the required information (which will vary from project to project) and also involves a consultation process with your neighbors, etc. Understandably, the planning process often takes longer... but don't be put off! A common misconception is that anything that will be approved sits within permitted development, and thus a planning application is more likely to just result in a 'no'. The reality is that brilliant bespoke projects can require planning permission because they are a bit more 'out of the ordinary'. For example you may want to maximise the scale (reasonably), you may want to make a building look better, or you may want to use beautiful natural materials ...

don't be put off from doing these things at the outset!

Structural glass link extension, natural stone, interior architect. Graham O'Connor Architecture, Guildford, Surrey

There are many methods that can be used to help increase your chances of achieving planning permission, and this is where a good insight from a professional is valuable. With a good and reasonable application, there is then often the opportunity for some negotiation with the planning department in order to achieve permission.


So if what you want to achieve is reasonable but requires planning permission, please don't rule it out.

Your home will likely be better for it, and there is a good chance it will become more valuable too.


Design and build is becoming an ever more popular route in the marketplace. On this route, I work with a trusted building company network that I have fostered for over 10 years. With us it will allow you to have a high-quality design that you know from the outset is going to keep on track with your budget expectations and be delivered in a timely manner; this is because you will have a genuine partnership between an experienced designer and experienced builders.


One of the most common regrets from people extending their homes is that they ran into problems with the transition from design and approvals, to the build itself. There are many possible reasons for this, but some of the most common are sourcing a good and available builder; time delays; the cost of the project increasing from what was hoped, and worst of all the horror stories of a builder slipping drastically from their timeline / costs increasing / or a builder leaving a build when the work is incomplete. You would have the peace of mind that all of this was being managed.

Why use our 'design and build' route?

Graham O'Connor Architecture. Property. Professional. Design and Build. Turn key. Architectural Design. Architect. Your home. Dream. Trust

Interior architect, interior design, bespoke kitchen, exposed steel, Graham O'Connor Architecture, Guildford, Surrey

Design and build has become a more popular route because the disparities from separating these functions have become more apparent in recent years. We have seen far too many disappointed clients when they find out that they simply cannot afford what has been designed!


When dealing with 5 and 6 figure sums, a project only needs to be a few percent out to have a big impact, and we've seen projects as much as 40% out in recent years! ... which is pretty heartbreaking for clients.

So, what can cause the disparity?

  • Building materials have seen huge increases. Many clients may for example have historical knowledge or know someone who did a similar extension a few years ago, but that extension could cost tens of thousands of pounds more in today's market.

  • Architects and designers do not always design to budget, and this has become a greater divide as a result of material increases. We have redesigned numerous projects to meet a budget after approvals have already been achieved.

  • Builders do not always build to budget either. There is nothing worse than going with a quote you can afford, and then being asked for more money because someone has under-quoted their work. The message here is the same as always- you want a good and trusted builder.

bespoke eaves window, natural light, Interior architect, Graham O'Connor Architecture, Guildford, Surrey

Other Benefits of Our Design and Build Route:

  • We are experienced specialists in our field. Some design and build companies are builder-led, i.e. they lack a specialist designer, jeopardizing the quality of the project.

  • The building companies i work with usually runs 3-4 projects at once. This means they are not only very experienced, but also more likely to have availability to start your project than a smaller scale builder doing 1 project at a time, and thus sometimes booked up more than a year in advance. With design and build, builders also know about your project further in advance.

  • We also offer an honest route, and you can still explore other options during the process. One example is that you may get to the building part of your quote and want to see other quotes too- we will support you in this.

It is also important to note that with many building projects, but particularly design and build, initial quotes will involve 'provisional sums'. Whilst the price for building materials, labour, etc. is all fixed; some things are more variable when a client comes to choosing the specification. A good example is electrical plans for sockets and lighting. You may spend less than the provisional sum and get some money back- or you may decide you want a higher specification and spend a bit more, in turn increasing your bill a little.


In conclusion, design and build is a good route when using experienced professionals in both fields. It can vastly reduce the headaches of designing something to budget, finding a good builder, delivering the project without delays, avoiding significant cost increases, and ensuring that your build project does not become a horror story.

Please get in touch if you are considering this route.

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