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Ground floor house extension

Updated: Mar 16

Everything you need to know about ground floor house extensions. Including information about the architectural design, planning and building process. Costs involved in building a ground floor extension. Inspirational images from real ground floor house extension projects designed and built by LCCL Construction. Learn more about the different types of ground floor extensions and which ones could be suitable for your home.


Interior view of a ground floor extension with Bi-fold doors by LCCL Construction
Ground floor extension by LCCL construction

What is a ground floor house extension?


Ground floor extension is really a generic term which can be used to refer to multiple different types of extension but generally it just means an extension on the ground floor of the property, usually for the purpose of creating a larger kitchen/dining/living space at the rear of the property. Home owners looking to add a ground floor extension are typically hoping to add space and simultaneously reconfigure existing space in the ground floor. For example adding a 3 meter deep full width rear extension whilst at the same time rearranging the ground floor structure to get rid of a small galley kitchen and separate dining area. Creating a large social space where friends and family can cook, socialise, do homework, relax and even work from home are in and a ground floor extension is the perfect way to make this possible. We have also seen a trend for removing the laundry elements from the kitchen and adding a utility room where space allows or a utility pod where space is limited. This reduces noise levels in the kitchen and allows for greater storage utilisation in the kitchen area. This has obviously had a big impact on the way kitchens and extensions are designed. Adding open plan spaces to properties that were built with multiple smaller rooms at the rear requires careful architectural design and critically this design must be supported by accurate structural drawings and calculations. At LCCL Construction we deliver all of these services efficiently and expertly as part of our design and build package.


Interior view of a ground floor extension by LCCL Construction
Ground floor extension by LCCL Construction

What are the benefits of a ground floor extension?


Whether your aim is to increase the overall sqm of the property, enlarge kitchen size, add living space, a utility room the benefits of a ground floor extension are numerous:


  • Utilise otherwise unused space to increase the size of the home.

  • Improved saturation of natural light in the downstairs areas through addition of skylights/lanterns

  • Install downstairs/understairs wc.

  • Added flexibility to the layout of the home

  • Create space for a large open plan kitchen diner and casual living space where everyone can spend time together

  • Add space to work from home

  • A generously sized utility room can be added to free up space in the kitchen and reduce noise from washing machines/dryers

  • Add a boot room to reduce dirt and clutter coming into the house

  • Create much needed extra storage space

  • A new patio at the rear or private courtyard can be created at the side

  • Extra 16m2 to 60m2 of additional space

  • Potential for additional space to be added to the first floor too in some circumstances

  • If the garden space is small this is a good solution

  • Extra storage and usable space for everyone in the home to enjoy


A modern neutral bathroom built by LCCL Construction
New bathroom by LCCL Construction

What type of space can I add to my home?


There are many layout options available to homeowners looking to add a ground floor extension to their home. Several factors come into play when settling on the final layout

  • The size and layout of the existing home

  • Whether you want to make moderate or substantial adjustments to the structure of the existing house or alternatively add space with minimal structural and or layout alterations to the existing house

  • How much budget you have available for the project

  • If you are looking to achieve an open plan layout/partially open plan or to add multiple rooms


For more inspiration have a look at our current and completed projects on our Instagram https://www.instagram.com/lcclconstruction/


Exterior view of a brick built ground floor extension by LCCL Construction
Brick built ground floor extension by LCCL Construction

Do I need planning permission for my Ground Floor Extension?


In many cases it is possible to build a ground floor extension as a permitted development project, subject to specific criteria being met. This is not always the case though depending on the size and scale of the extension and in some cases a full planning application will need to be made to your local planning authority. At LCCL Construction our expert team will be able to help guide you through the process.


Rules, known as ‘permitted development’ rights, allow you to extend a house without needing to apply for planning permission if specific limitations and conditions are met.


For all extensions:


  • Only half the area of land around the "original house"* can be covered by extensions or other buildings.

  • Extensions cannot be higher than the highest part of the existing roof; or higher at the eaves than the existing eaves.

  • Where the extension comes within two meters of the boundary* the height at the eaves cannot exceed three meters.

  • Extension cannot be built forward of the ‘principal elevation’ or, where it fronts a highway, the ‘side elevation’.

  • The work cannot include:

  • verandas, balconies or raised platforms.

  • a microwave antenna (e.g. TV aerial or satellite dish).

  • a chimney, flue or soil and vent pipe.

  • any alteration to the roof of the existing house.

  • On Article 2(3) designated land* the work cannot include cladding of the exterior.

  • The materials used in any exterior work must be of a similar appearance to those on the exterior of the existing house.


For single storey extensions:


  • Single-storey rear extensions cannot extend beyond the rear wall of the original house* by more than four metres if a detached house; or more than three metres for any other house.

  • Where not on Article 2(3) designated land* or a Site of Special Scientific Interest; and subject to ‘prior approval’, the limit for single-storey rear extensions is increased to eight metres if a detached house; or six metres for any other house.

  • This requires that the relevant Local Planning Authority is informed of the proposed work via a prior approval application.

  • Single-storey rear extensions cannot exceed four metres in height.


For Extensions more then one storey:


  • Extensions of more than one storey must not extend beyond the rear wall of the original house* by more than three metres or be within seven metres of any boundary* opposite the rear wall of the house.

  • Roof pitch must match existing house as far as practicable (note that this also applies to any upper storey built on an existing extension).

  • Any upper-floor window located in a ‘side elevation’ must be obscure-glazed; and non-opening (unless the openable part is more than 1.7 metres above the floor).

  • All side extensions of more than one storey will require householder planning permission.

  • On Article 2(3) designated land* all rear extensions of more than one storey will require householder planning permission.


Learn more about the process of building a ground floor extension by watching our useful construction videos here:



What are the types of ground floor extension?


Ground floor rear house extension

Design and Build Rear House Extension with a pitched or flat roof

Estimated cost: from - £45,000.00


External view of a rear house extension by LCCL COnstruction
Rear house extension by LCCL Construction

Optional Extras:


  • Skylight or small lantern

  • Bi-fold doors

  • Kitchen

  • Floor finishing

  • Patio at rear of the property

  • Downstairs Bathroom



Read more about Rear House Extensions









A new modern kitchen with island inside a kitchen extension by LCCL Construction
Ground floor kitchen extension by LCCL Construction

Wrap around house kitchen extension

Design and Build Wraparound Extension.

Estimated cost: from - £57,700.00


Optional Extras:

  • 1 x Skylights or Lantern on flat roof

  • Bi-fold doors

  • Kitchen

  • Floor finishing

  • Utility room

  • Patio at rear of the property

  • Downstairs Bathroom




Interior view of a sidereturen extension
Interior floor extension by LCCL Construction

Side return kitchen extension

Design and Build  Sidereturn Extension Pitched Roof.


Estimated cost: from - £46,000.00

Optional Extras:


  • 3 x Velux

  • Bi-fold doors

  • Kitchen

  • Floor finishing

  • Patio at rear of the property

  • Downstairs Bathroom




Do I need a Party Wall Agreement for my ground floor house Extension?


For the majority of homeowners in London who are living in terraced or semi-detached properties a Party Wall Agreement will be required to carry out the work required to build a ground floor extension. The way in which the Party Wall Matters are resolved will be largely influenced by the responses received from your neighbours when the initial letter is sent, so bare that in mind in the run up to the build! For detached properties a Party Wall Agreement may be required depending on how close to the boundary you intend to build.


What is the cost of a ground floor house extension?


You can use our "instant quote calculator" and find out the cost in seconds! for both design and build, architecture services or just construction services depend what stage you are in and what you have so far completed.

We have experience of over 17 years in design and construction of loft conversions and home extensions in London and Hertfordshire areas and have worked out a unique calculation formula that you can find out to what your house extension and loft conversion will cost in seconds.


Is my house suitable for a ground floor extension?


The ground floor extension can be created on end of terraced houses, semi detached houses or detached houses including Period style properties, Edwardian, Victorian or modern homes that have space to the side of the existing ground floor.


Will a ground floor extension add value to my home?


A ground floor extension brings many benefits to the house and naturally homeowners are keen to find out if the work completed adds value to the property. According to The Times Money Mentor (source https://www.thetimes.co.uk/money-mentor/article/best-ways-add-value-home/) building a ground floor extension can add around 15% to the value of the existing house. It is also widely thought that having a large open plan kitchen makes a property more easily saleable.


How can Lccl Construction be of help?


Do you require a loft conversion  and house extension to add extra space?



Then look no further get in touch with us for a detailed free no obligation quote. We can accommodate a very quick turnaround. Our loft conversions and house extensions come with 10 year guarantee and 12 month workmanship guarantee.

Use our instant quote calculator for a quote about your project whether construction only or design and build.


Use our Free consultation call booking system to schedule a call at the time and date that suits you best.



Telephone: 020 8037 7332






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