Renovations & Extensions | What to Know Before You Start

Q: Do I need planning permission for a home extension or renovation?

Whether you need planning permission depends on the type of work and the rules that apply to your property. Some smaller changes may fall under permitted development rights, meaning you don't need formal planning permission if you stay within specific limits. However, many larger projects — such as substantial extensions or works in conservation areas — will require a formal planning application submitted to your local council. It's important to check with local planning authorities before starting work to avoid enforcement actions.

Q: What is the difference between planning permission and building regulations?

Planning permission and building regulations are two separate systems. Planning permission focuses on whether the design, size, and impact of a project are acceptable in the context of local and national planning policies. In contrast, building regulations ensure that the actual work meets minimum safety, structural, energy efficiency, fire safety, and accessibility standards. Most extension and renovation projects will need building regulations approval, regardless of whether planning permission is required.

Q: What are permitted development rights and how do they help?

Permitted development rights allow homeowners to undertake certain home improvement projects without having to apply for full planning permission, provided the work meets defined criteria such as size, height, and location limits. Common examples include modest rear extensions and loft conversions, subject to conditions. Even where permitted development applies, you may still need building regulations approval, and rights can be restricted in conservation areas or by Article 4 directions.

Q: How long does a home extension take to complete?

The timeline varies depending on the size and complexity of the project. A typical single-storey extension may take around 10–16 weeks to build once construction begins. However, the full process — including design, planning approval (if required), and sourcing contractors — can take several months before work even starts. Weather conditions, material delays, and structural surprises can also impact timelines. Proper planning and clear communication with your builder can help keep the project on track.

Q: Will an extension add value to my home?

In many cases, a well-designed extension can increase property value, particularly if it adds functional living space such as an additional bedroom, open-plan kitchen, or extra bathroom. However, the level of return depends on local property prices and whether you exceed the ceiling value for your area. Over-improving compared to neighbouring homes may limit financial return. It's wise to research local market conditions or speak to an estate agent before committing to a large investment. Thoughtful design and quality workmanship play a key role in maximising value.

Q: What are the most popular types of home extensions?

Some of the most common extensions include rear extensions to enlarge kitchens, side return extensions for Victorian and terraced homes, loft conversions for additional bedrooms, and wraparound extensions that combine side and rear space. Garden rooms and home offices have also grown in popularity in recent years. The best option depends on your property layout, budget, and long-term needs. Each type has different planning considerations and structural requirements. Choosing the right extension should balance practicality, aesthetics, and value.

Q: How can I minimise disruption during building work?

Clear planning and communication with your builder are essential to reducing stress during construction. Establish agreed working hours, access routes, and dust protection measures before work begins. Setting up a temporary kitchen or alternative living arrangements may be necessary for major renovations. Keeping neighbours informed can also help maintain good relationships. A well-organised contractor with a clear schedule will significantly reduce delays and unexpected disruption.

Introduction
Planning a Renovation: Where to Begin
Choosing the Right Materials for Your Extension
Heating, Plumbing & Insulation Considerations
Decorating After Renovation
Finishing Touches: Skirting, Coving & Doors
Built Around Your Project, Backed by Experience
Further Reading & Resources
Are You a Trade Professional?

Renovating or extending your home is one of the most rewarding investments you can make, but it comes with no shortage of decisions. From the early stages of scoping your project to the finishing touches, every step needs careful planning and the right materials.

Whether you're a homeowner managing your own renovation, a DIYer tackling improvements room by room, or a trade professional delivering quality work for clients, this guide will help you plan with confidence. We’ll cover the essentials: planning regulations, material choices, heating and insulation, decorating timelines, and finishing products.

With over 45 years of supporting London’s building trade and local communities, MP Moran is here to supply not just the products, but the advice, tools, and services to help you get it right.

Planning a Renovation: Where to Begin

Every successful renovation starts with a clear plan. Before you begin comparing materials or booking trades, it’s essential to scope the work properly, understand your legal responsibilities, and set a realistic budget.

Depending on the scale of your project, you may need to:

Check planning permission or permitted development rights
Review building regulations for extensions, insulation, and structural changes
Decide what’s DIY-friendly and what needs professional input
Set timelines and allowances for design, prep, and build phases

The earlier you get organised, the fewer surprises down the line, especially when coordinating materials, deliveries, or specialist contractors.

Choosing the Right Materials for Your Extension

The materials you choose for your extension will have a direct impact on cost, performance, and how efficiently the space functions once it’s complete. It’s not just about finding what fits; it’s about understanding how each product contributes to structural integrity, insulation, energy ratings, and the overall finish.

When planning an extension, think about:

Walls & Structure: Bricks, blocks, and timber framing
Insulation & Efficiency: PIR boards, mineral wool, or natural options
Internal Build: Plasterboard, fixings, door linings, flooring
Sustainability: FSC® timber, low-carbon products, high thermal ratings

A gloved hand removing algae from a roof with a pressure sprayer.

Heating, Plumbing & Insulation Considerations

If you’re renovating or extending, it’s important to think beyond the walls. Heating, plumbing, and insulation play a huge role in the comfort, efficiency, and compliance of the finished space, and making the right choices early on can prevent costly rework later.

Heating Options for Renovated Spaces

Extensions often include open-plan kitchens or living areas, so choosing the right heating system is crucial.

Two common options are:

Radiators: Familiar, easy to install, and available in a wide range of sizes and styles
Underfloor Heating (UFH): Excellent for space-saving and even heat distribution, especially with tiled or engineered flooring

Plumbing Considerations

If you're adding bathrooms, utility rooms, or kitchens, think about:

Extending or relocating pipework from the main system
Water pressure and flow to new fixtures
Heating system capacity (boiler upgrades may be required)

Plumbing decisions also impact flooring, wall build-ups, and appliance placement, so they should be made before finishing stages.

Insulation & Efficiency

Insulation is no longer optional, it’s a legal and practical necessity.

Depending on the build type, you’ll need:

Wall insulation: Cavity, internal, or external
Roof and loft insulation: Between and over rafters
Floor insulation: Especially important with UFH systems

Choosing high-performance insulation can help improve your SAP (Standard Assessment Procedure) rating, which is crucial for building control approval in many projects.

Decorating After Renovation

Decorating is one of the most satisfying parts of a renovation, but getting it right means knowing when to start and which products to use. Rushing in too soon, especially with freshly plastered walls, can lead to poor finishes and wasted time.

Before you begin decorating, it’s important to:

Let new plaster fully dry. Depending on the conditions, you’ll have to wait a recommended amount of time before painting fresh plaster
Apply a mist coat as a breathable base layer before any painting
Choose the right paint. Trade options can offer better coverage and long lasting results but it all depends on your project
Use quality tools such as rollers, angled brushes, filler, and sanding blocks to make all the difference

Finishing Touches: Skirting, Coving & Doors

The finishing details are what give a renovation its character. Elements like skirting boards, coving, and internal doors can dramatically change the look and feel of a space, and they’re just as important as the larger building materials.

Skirting & Architrave: Available in various profiles and sizes to suit traditional or modern interiors
Coving & Decorative Mouldings: Adds definition and depth to ceilings, especially in period-style rooms
Internal Doors: Choose from solid, glazed, panelled, or fire-rated options for each room’s needs
Installation Tools & Kits: From mitre boxes to adhesives and fixings, the right tools make all the difference

Choosing quality finishes will elevate your project and give it a professional, polished look.

Built Around Your Project, Backed by Experience

Whether you're planning a full renovation, a side return extension, or a few key home improvements, success depends on having the right materials, advice, and support at every stage.

At MP Moran, we’ve been working with trade professionals, homeowners, and self-builders across London and Hertfordshire for nearly 50 years. We understand the challenges that come with home improvement, and we’re here to help you get it right.

Here’s how we support your renovation:

Tailored Advice: In-branch specialists can help you choose the right materials, tools, and quantities for your project
Sustainable Options: FSC®-certified timber, eco-friendly products, and a focus on reducing waste and emissions
Reliable Stock & Delivery: Locally held stock and efficient delivery services to keep your job on track
Specialist Services: Our in-branch services span everything from sheet material cutting and landscaping display to tool repairs and skip hire
Flexible Fulfilment: Click & collect, local delivery, or in-branch purchases to suit how you work

Need help with a specific project? Contact our team or visit your local branch.

Planning & Completing Renovations, Extensions & Home Improvements

Table of Contents

Planning a Renovation: Where to Begin

Choosing the Right Materials for Your Extension

Heating, Plumbing & Insulation Considerations

Heating Options for Renovated Spaces

Plumbing Considerations

Insulation & Efficiency

Decorating After Renovation

Finishing Touches: Skirting, Coving & Doors

Built Around Your Project, Backed by Experience

Further Reading & Resources

Are You a Trade Professional?

FAQ: Planning & Completing Renovations, Extensions & Home Improvements

Do I need planning permission for a home extension or renovation?

What is the difference between planning permission and building regulations?

What are permitted development rights and how do they help?

How long does a home extension take to complete?

Will an extension add value to my home?

What are the most popular types of home extensions?

How can I minimise disruption during building work?