In the UK one of the most common home improvement projects is the extension. You can extend the rear, side or front of a property, and can be single, double, even triple story.
Some single story extensions fall under Permitted Development and therefore do not require planning permission. Any proposed work must fall within the following limits and conditions:
- Extension cannot be higher than the highest existing point of the roof, and cannot exceed 4m in height
- Extensions mustn’t extend more than 4m past the rear wall of original property if the house is detached, or 3m for other houses such as semi-detached and terraced
- Materials used must be in keeping with the existing external appearance of the property
- Cannot surpass half of the original properties width
This is not an exhaustive list of conditions so do get in touch if you have any further questions about the suitability of your project.
Of course the planning process is rarely a straightforward one. Extension projects are considered ‘remodels’, as work is being done to the internal structure of the house. Therefore applying for, and receiving householder planning permission is usually necessary in order to carry out any substantial work on your property.
Developing Your Extension
Step 1: Initial Conversations and Feasibility Studies
At this very first stage you might not have a complete visual in mind for what your extension will look like. Or, you might know exactly what you want, you just need help ironing out all the specific details.
An initial consultation with a design and planning professional can make all the difference in your project running smoothly and to budget. You will gain insight into what is possible legally, financially and structurally. Bring your ideas and be flexible!
Information gathered at this stage include various factors; zoning regulations, environmental impacts, access to utilities, and site conditions. These past histories can help identify any challenges or limitations that may affect the design or construction process. Any planning constraints like previous articles or permitted development, whether your property falls in a conservation or area of natural outstanding beauty, will be checked and noted as well.
Timeline: typically 2-4 weeks
Step 2: Design
The final concept will be agreed upon, and from that a workable design is created. These will include relevant technical and structural details like elevations, drainage, safety, materials, energy, efficiency.
All this information affects construction and will be included within the planning permission package, along with the existing information pack gathered in the previous stage.
During this step, you, or your nominated design professional, will likely consult with any third party collaborators such as Technical and Structural Engineers, Energy Assessor, Arboriculturist to provide relevant information for your planning submission.
Timeline: typically 2-4 weeks for discussion, revisions and finalisation of concept
Step 3: Planning Permission
If your proposed project falls under Permitted Development then you are not obligated to follow this step or contact the local authority for planning permissions. However we ALWAYS advise, regardless of the project, you making the council aware of any intent to develop or build.
If Permitted Development does not cover your project, then at this stage it’s time to achieve the legal permissions necessary to build by submitting a planning application via Planning Portal.
The ‘Planning Pack’ will include all proposed plans, materials, third party documents and existing site and location information. Once this is done, we will manage the process, responding to any queries and make revisions if necessary.
Timeline: planning permission typically between 2-8 weeks, but due to back log within the local authority it may take several months.
In this stage Ellis+Company work towards achieving ‘Granted’ planning permission from the Local Authority. The concept sketch is developed into detail where style, form, materials, and project impacts are discussed. From this, a ‘Planning Pack’ is compiled – this includes the detailed proposed drawings, and any third party documentation and additional forms that may need filling out. We will submit and monitor the application, keeping you updated throughout the process Our Part #2 fee would be invoiced upon submittal of planning application.
Step 4: Building Control Regulation
Comprehensive and concise technical drawings will be submitted to Building Control. These detail various details such as; structural feasibility, fire safety, accessibility, drainage, thermal performance and ventilation. They will be tested for compliance with building codes on safety, insulation and energy standards.
Timeline: 3–5 weeks for approval
Step 5: Manufacturing and Construction
Once Building Control has approved the extension we compile all drawings, documentation, and third-party reports into a ‘Tender Package’. Often this includes appointing a lead contractor to over see the whole build, whilst also project managing the construction and completion phase.
You can also hire an architectural professional like design and planning consultants. They manage the process for you, design, submissions, tendering out your project to contractors and trade professionals.
Step 6: Final inspection and Handover
Final inspections are carried out, and the project is signed off by Building Control. All the legal documents are complied and given to the client. The consultant will update the property records, and if there is any snagging to respond to, they respond to that and see the build through to completion of the clients satisfaction.
