What size extension can I build without planning permission?

PD allows single-storey rear extension up to 3m deep (terraced/semi-detached) or 8m (detached).

How much is the average house extension?

Outside of London, the approximate cost per m2 varies between £1,200-£1,500. In London, this increases to £1,500-£2,000+. Should you want a two-storey extension, add 50% to the cost and for a bathroom or kitchen, between £5,000-£10,000.

Can my neighbour build an extension up to my boundary?

Yes if planning permission or permitted development allows it. However, if they make use of your shared wall, then a Party Wall Agreement will be required.

Do I need an architect for an extension?

Using an architect can be very expensive. By using an architectural technician such as Fast Plans, you save time and money. We take care of the design, planning and technical drawing phases.

HOUSE EXTENSION PLANS

We’ve made it simple to add space and value to your home

Want your home to work harder for you? With a home extension, you can easily add valuable space and extra utility to your property. We have a successful track record of working with customers like you to create their dream home extensions.

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Or call us on: 0 208 154 5569

Illustration Of A House Extension Architect Preparing House Extension Plans

The experts at handling your design needs from start to finish

We offer a personal touch that goes well beyond just the plans. With our experience in all aspects of home extension design, we can give you advice on planning permission considerations, outline options for extensions and deal with the planning authorities. We aim to make the home extension process as simple as possible for you.

A full measured survey within 1 week

A full measured survey to be undertaken within 1 week of accepting our proposal.

Get a first draft within 2 weeks

First draft drawings delivered within 2 weeks of the date of the survey, GUARANTEED.

Unlimited design revisions

UNLIMITED revisions during the design phase means we will keep revising the designs until you are happy with the results.

Full engineers drawings & calculations

We prepare and provide all of the engineering calculations and structural drawings required to complete your project.

All the drawings you need

We supply all the drawings required to obtain planning permission, building regulation approval and for your contractor to price and construct your project.

Full planning application management

We free you from the stress, time, and effort of planning applications. We handle your entire application from start to finish.

Our packages include everything you need, nothing you don't

We're serious about quality and professionalism. We don't like surprises either. Our prices are competitive and fixed: no add-ons, no extra costs for engineers calculations, no percentage-based fees, no silly caps on revisions, and no charges for amendments requested by planning or building control. Avoid escalating costs from the outset with fixed design fees!

Full Service Design & Planning Extension Package

£1,680

(incl VAT)

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Detailed measured property survey

ALL drawings required by local authorities

Full planning or PD drawings

ALL drawings required by building control

FULL planning application agency services

ALL drawings required by your builder

ALL engineers drawings and calculations

Non-standard projects may incur additional charges

UNLIMITED revisions during the design phase

Extension plans that fit your lifestyle

We help make the process of adding value to your home easier by providing you with all the design and drawings services needed to get things started in one place.

You can rely on our experts for comprehensive guidance throughout the entire process - from obtaining the right planning permission to ensuring that your chosen design maximises your investment.

Over the past 15 years, we have designed home additions that add value to our customers' homes. Our designers can work with you to create the perfect design for your needs, tailored specifically to meet your requirements. Our team can guide you through any project, from redesigning your living spaces to extending your entire house to correcting design flaws. With the help of our specialist house extension architectural designers, we can create innovative designs, prepare the technical drawings, and submit planning applications to make sure you get the most out of your space.

REAR EXTENSION PLANS

Add an extension to the back of your house

A rear extension is a great way to add a bit of extra space (and value). In order to take advantage of the additional space, homeowners are often building larger kitchens, additional bedrooms or bathrooms, or adding a home office. Adding an extension to your home is a great way to increase the value of your home and convert unused space in the backyard.

Increase living space by expanding the kitchen, adding a bathroom, or adding a bathroom. Any of these improvements will boost the value of your home.

Create extra living space out of unused garden space.

Illustration of a rear house extension during a house extension plans project

Illustration of a side house extension during a house extension plans project

SIDE EXTENSION PLANS

A space for everything, a place for everyone

If you don't want to reduce the size of your back garden and aren't using the land on one (or both) sides of your house, then an extension on the side of your house can be an excellent option. In addition, it often complements the layout of your home. A side extension is an excellent option since it provides an uninterrupted line of floor space from the front to the back of the property.

A side extension is the perfect way to increase your living space without radical changes to your garden.

Create an additional room for a bathroom, a utility room, or even a conservatory or a garden room.

WRAPAROUND EXTENSION PLANS

More space and light for your home

A wraparound extension wraps around the sides of your home, creating a new L-shaped addition to the rear and side. The wraparound extension gives you plenty of design options to create new spaces like playrooms, utility rooms and bathroom additions. Older homes that have 'dead' alleyways to one side and the back of the property are good candidates for these popular extensions.

By creating an 'L' shape extension, you can create more light within your home and open up your kitchen area.

With the addition of beautiful, new rooms, you'll be able to enjoy light and space in a different way.

Illustration of Wraparound House Extension Design

We create happy homes, one project at a time

Re-imagine your home

Extending your existing home can give you more living space, improve the layout of your property and make it more functional and attractive.

Add more to your home

Extensions are one of the best ways to both increase value and to ensure that your house is future-proofed while staying in your preferred neighbourhood.

The perfect space

A home extension gives you the opportunity to personalise it according to your family's needs. Every aspect can be tailored to your exact specifications.

Getting the planning permission you need

Permission for an extension does not have to be as complicated as it first appears. Permitted development rights allow you to do a lot of work on your home without getting planning permission.

The permitted development rights allow homeowners to expand without getting planning permission as long as they follow strict guidelines.

Besides the strict guidelines regarding permitted development, some types of properties cannot be developed. These include flats, maisonettes, and listed buildings. Furthermore, properties within conservation areas are not automatically excluded from the scheme but are subject to stricter PD requirements.

Extensions to homes need one of three types of permission planning: permitted development, full planning permission, or householder planning application. The best approach is determined by the type of property, the location, and the proposed design.

With the support of our project planning team, you'll be guided and advised in choosing the right route. Technical drawings that comply with your local authority's guidelines are provided by our technical drawing service. We also manage planning permission applications. Thus, we can reduce the likelihood of errors in your application as well as work one-on-one with your local authority.

OUR DESIGN AND PLANNING PROCESS

Relax, we’ve got this - We’ll take care of the entire process for you

Over the years, we have worked with hundreds of clients and have developed a proven process to make your loft conversion or extension project cost-effective, accessible, and hassle-free.

1

Undertake a full measured survey

We’ll carry out a survey of your home, which will take approximately 1–2 hours with access needed to all rooms of your property.

2

Carry out initial designs

We will share first drafts of your drawings within 1-2 weeks, and there are unlimited revisions during the design phase.

3

Submit drawings to local authorities

We manage the entire planning process on your behalf (with you paying the council fees). Any changes requested by the planning department will not incur any additional costs.

4

Complete engineers drawings and calculations

Upon local authority approval, we’ll complete the building regulations drawings and engineer calculations.

HOUSE EXTENSION CONSIDERATIONS

Here to guide you throughout the process

There are a number of things you should consider when thinking about how to extend your home. Our team will guide you throughout the entire process. These factors include things such as the purpose of the extension, your budget, your time-frame, utilities and services (both existing and proposed), neighbouring properties (and any party wall issues), design and style, planning permission, building code compliance, existing foundations, sewer considerations, and heating and boiler capacities.

From initial design concepts to obtaining permits and approvals, we help you through all stages of your project.

Our surveyors can identify potential problems before they arise, ensuring your house extension project is a success.

Illustration of The Various Considerations When Undertaking A House Extension

Frequently Asked Questions

A house extension project can be an exciting endeavour but it can also be overwhelming. There are a lot of questions to ask yourself, as well as a lot of decisions that need to be made. We've put together a list of some of the questions we normally receive from our clients, with honest and accessible answers.

What size extension can I build without planning permission?

PD allows single-storey rear extension up to 3m deep (terraced/semi-detached) or 8m (detached).
How much is the average house extension?

Outside of London, the approximate cost per m2 varies between £1,200-£1,500. In London, this increases to £1,500-£2,000+. Should you want a two-storey extension, add 50% to the cost and for a bathroom or kitchen, between £5,000-£10,000.
Can my neighbour build an extension up to my boundary?

Yes if planning permission or permitted development allows it. However, if they make use of your shared wall, then a Party Wall Agreement will be required.
Do I need an architect for an extension?

Using an architect can be very expensive. By using an architectural technician such as Fast Plans, you save time and money. We take care of the design, planning and technical drawing phases.

Let's get started

Finding the right professionals can be time consuming and expensive. You could end up disappointed with their work or worse.

Our experienced team is approachable, friendly and helpful and easy to deal with. We will guide you through the process of design, planning permission and building regulations allowing you to relax knowing that it’s us who will steer you in the right direction.

Request a FREE consultation with our design team

Request your FREE no-obligation proposal

Illustration of Fast Plans Customer Service Team Running Through House Extension Plans Checklist

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YOU ARE IN THE RIGHT PLACE

Dream it, design it together

When it comes to home extensions and loft conversions, you want to get it right the first time. Our team of experienced and highly qualified architectural designers and surveyors have years of experience in bringing clients’ dreams to life.

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