The Laurels | Planning project

Home Extensions – Surrey

There are a huge number of things to consider when you are planning an extension or significant alterations to your home!


Here are a few questions to ask yourself before you begin:


Do you really need to extend?

It’s worth considering whether the current property could be adapted or reconfigured to meet the needs that you have identified. There are often many solutions, but sometimes you ‘can’t see the wood for the trees’.


It often helps to have an outside view. This is where a good architect can translate your ideas into reality or see things that you can’t through their experience.

Who’s going to manage the project?

Are you going to manage this yourself or rely on others; if so, who? Whilst some aspects of the process can be done by yourself, it is best to seek advice and make sure that you know what’s involved from start to finish.


We would always advise having a good architect and bringing in a good contractor at the very least. You will need to bring in other professionals, but the architect and contractor can advise you as to who and when.

Before you start planning your home extension, download our guides to make sure you avoid wasting time and know what to expect in terms of professional fees.

What’s involved?

Depending on the project, the stages of a home extension are usually:


Step 1 – A Survey

Step 2 – Concept Design

Step 3 – Planning & Building Regulations

Step 4 – Before Building Starts

Below we set out the steps in detail together with the answers to some frequently asked questions.

Avoid Costly Mistakes

Building an extension can be one of the best ways to leave your mark on your home and can even add value, but you need to fully understand what’s involved.


Download our guides to avoid stressful and expensive mistakes.

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Step 1: Survey

FORM’s resident Civil Engineer and extensions expert, Andy Manington I.Eng M ICE answers your home extension questions:

Andy joined Form as a co-director in 2015, bringing complementary building design and Structural Engineering skills to the practice.


With a wealth of experience across all sectors of development, Andy successfully delivers quality structural design services for simple and complex projects.


Andy feels that many people are daunted by starting a building design project, whether it’s a simple extension or major new development, and is passionate about helping you understand what’s involved so they have clear expectations from the outset:


“Before I start working with a client I explain the whole process from ‘Do I need planning permission?’ through to setting out what will happen before and during construction. It’s all about having an open approach and being absolutely clear about what the client really needs.”

What surveys do I need?

The three most common surveys are:


  • A full measured survey to calculate the internal square floor area of your property in order for us to proceed with detailed and accurate plans.
  • A topographical survey or grounds to pick up any level changes and tree roots that may have an influence on a basement excavation or extension from their roots. This may include trees in the grounds of adjacent properties.
  • A utilities survey to identify any underground water and sewage services that may impact the design of your new extension or basement excavation.


We can either do this ourselves or bring in a land surveyor with all the relevant equipment for more complex jobs

How much will my house extension cost?

The more important question is how much can you invest and will it be worth it for you in the long term? Are you making an emotional investment or a practical investment?

How long will the project take?

It’s not just the cost that you need to consider: work on your property will impact your life, but it’s much easier to deal with this though if you understand how long it will take.


You will need to plan your life around the work and in some instances may need to consider moving out for the duration of the construction period and factor this into your budget.

Step 2: Concept Design

FORM’s resident Architect, Mike Chidzey BA (Hons) DipArch RIBA answers your home extension design questions:

Mike’s love of contemporary design shines through his extensive private and public sector portfolio. Residential, commercial and industrial architecture projects include hotels, mixed-use schemes, retail parks, homes and apartments, car showrooms, recording studios and marinas.


Mike is passionate about creating extensions that don’t just look great, but which fit their intended use and setting: “Our combination of technology and experience makes us a formidable combination for our clients. At Form Design Group, we excel at communicating ideas and can show a client clear visuals that let them see a design in action, which really distinguishes us from non-chartered ‘architect designers’ and plan-drawers.

What’s the difference between an architect and an architectural designer or technologist?

To call yourself an ‘Architect’ in the UK you must be registered with the Architect’s Registration Board (ARB), which is there to protect your interests as a member of the public. The professional body requires all practising architects to carry insurance, this is something you should ask anyone if you are considering appointing them.  Members of the RIBA and ARB must adhere to their professional code of conduct.


Architects are generally more ‘design led’ with greater interest, experience and training in the aesthetic and spatial qualities of a project. Whereas Architectural Technologists often just have experience and training in the science and technology of building, e.g. how and why they are constructed in a certain way, using certain materials.


Good architects also understand the science and technology of building, as it’s part of their training, which is more extensive.


Unfortunately, anyone can call themselves an ‘Architectural Designer’ or use some derivation of the term or offer ‘Architectural Services’.  Qualifications and experience are key.

Can’t I design it myself?

For building projects, it’s always worthwhile using a qualified design professional.

They can help you find the best design solution for your brief, can advise you on your budget and how to get the best value for your project. They’ll guide you through the maze of planning, building regs, freeholder consent and party wall issues.

Step 3: Planning and Building Regulations

FORM’s resident Planning expert, Paul Uttley BSc (Hons) DipTP MRTPI answers your home extension planning permission questions:

Paul is a Chartered Town Planner with decades of experience in planning from working at senior levels in local government and the private sector.


He has a high success rate in getting clients’ plans accepted first time, thanks to his deep understanding of the UK planning system from the public and private sides of the fence, from strategic planning policy through to development proposals.


His mission is to make sure property and land owners understand the opportunities their asset can provide: “I offer straightforward advice and take an innovative approach to any planning challenge, but I never recommend ideas that can’t be delivered. At FORM Design Group, we provide good advice from the outset, then lead our clients through the planning process so they get the best results.”

Will I need to apply for planning permission?

In a very small number of cases, work can be carried out under what’s known as permitted development. However, in the majority of our clients’ cases a planning application is needed given the scope of work.  Once we have a clear understanding of exactly what you’re trying to achieve, we can advise further.

My house is listed / I live in a Conservation Area. Does this have an impact?

Yes, this does have an impact.  It doesn’t mean that you can’t extend and alter your property, you just need to take into consideration the significance of the heritage asset and the impact that your proposals will have.


FORM employs specialist and qualified Conservation Architects to deal with issues which arise when dealing with Heritage assets.

How long will it take for me to get planning permission?

This varies depending upon the size and complexity of the project and the local authority. Most straightforward domestic planning applications are decided within 8-12 weeks.


Our in-house Planning Consultants have complete knowledge of the planning process and over the years have established strong relationships with local authority planning departments.

Are we guaranteed to get planning permission?

Nothing is guaranteed, but we do pride ourselves on our high success rate for planning applications.

The English planning system is fairly prescriptive but the final decision is made by the individual planning officer or by committees, and their views can, as you would expect, be highly subjective and open to a broad interpretation of the ‘rules’.

Step 4: Before Building Starts

Back to Andy:

Once planning consent has been granted and it is clear what you have consent for, and which conditions – if any – need to be addressed, this is the time to start preparing the detailed plans for Building Regulations Approval.


If these are not ready you are very likely to experience frustrations when the works can’t start because your builders won’t have detailed plans to work from, or are delayed because the building control officer has concerns.

What does a Structural Engineer do?

A Structural Engineer is responsible for the design of any type of structure so that it can fulfil a specific purpose, and remain safe, economic, and functioning throughout its intended life.


A Structural Engineer will investigate the immediate loads and demands on a structure along with any proposed changes and ensure the structure is designed to withstand those loads.

Will I need a Structural Engineer on my project?

Any proposed change to a building that involves moving or removing existing walls such as an opening through to a new extension or changes that will increase loads on the existing building such as loft conversions will require a Structural Engineer, to confirm that loads are safely transferred through the building and the property doesn’t fall down around you.


The Building Inspector will require any structural changes to have been reviewed by a suitably qualified structural engineer to gain Building Regulations approval.


FORM Design Group has its own in-house Engineers to advise on this aspect of the work.

What are building regulations?

Not to be confused with Planning Permission, Building Regulations are there to ensure that buildings are made to a minimum quality standard for such things as structure, fire escape, drainage, ventilation and insulation.


Building regulation matters are usually handled by Building Control Officers in the Building Control Department of your local authority but increasingly private licensed inspectors are an alternative.

Who do you have to inform about building?

Legally you must ensure that Building Control is informed of your intention to build prior to work commencing. This can be done via a Full Application or a Building Notice:


1. Full Plans – this requires a full set of plans and information to be submitted to building control before starting work. You can start work once you have approval.


2. Building Notice – With this type of application you are only required to submit an application form, a location plan (if an extension is involved) and the appropriate fee.


The building regulation plans, together with the structural engineer’s calculations, will provide your builder with the essential information to construct your project ensuring a sound structure which meets UK building regulation standards.


The majority of builders will also require both regulation plans and structural calculations in order to provide an accurate quotation for the construction.

How do I choose the best builder?

Selecting a building contractor is important and we would recommend approaching at least three local building companies.


We work with a network of builders that we could recommend and with which we have a strong working relationship.

Thinking about building an extension? We can help.

Examples of our Home Extension and Alteration Projects: