Choosing the right type of home extension is the decision that shapes everything else. Get it wrong and you spend money solving a problem that remains unsolved. Get it right and the house works better for the next twenty years.

Crownhill Building Services has been having this conversation with Milton Keynes homeowners since 2006. Here is the honest version of what we tell them.

Single Storey Extensions

A single storey extension adds floor area to the ground level of your home — typically pushing out into the rear garden. It is the most common type of extension we build across Milton Keynes and the reasons for that are practical rather than fashionable.

Most single storey rear extensions fall within Permitted Development rights. No planning application, no waiting on a council decision and no risk of refusal. That removes eight to twelve weeks from the front end of the project and eliminates a layer of uncertainty that puts many homeowners off starting in the first place.

Build time runs from eight to fourteen weeks depending on size and specification. CBS manages the full process — architectural drawings, Building Control registration, construction and final handover. One team from first visit to completion certificate.

The right choice if: the household needs more usable ground floor space and wants to move from decision to finished result without unnecessary delay.

Double Storey Extensions

A double storey extension extends the house across both floors simultaneously. The same footprint of groundwork delivers twice the floor area — which makes it the most cost-effective option per square metre of new space when the household genuinely needs both levels addressed.

Unlike most single storey projects a double storey extension almost always requires a full planning application to Milton Keynes City Council. That adds eight to twelve weeks to the front of the project and introduces an element of uncertainty that does not exist with Permitted Development work. CBS manages the entire planning process on your behalf — drawings, application, correspondence and approval. You do not deal with the council directly at any point.

Build time is longer than a single storey project. The disruption is more significant. But for the right household and the right house the result justifies both.

The right choice if: the household needs additional bedrooms or bathrooms upstairs at the same time as more space downstairs — or when maximising the long-term value of the property is the primary objective.

Kitchen Extensions

A kitchen extension is in practical terms a single storey rear extension with a specific brief — to transform the kitchen and dining area into a single open-plan space that connects properly to the garden.

The original rear wall comes down. The room pushes outward. Bifold or sliding doors open the whole rear elevation. A roof lantern or glazed panel brings daylight deep into the space. What were typically two separate underused rooms become one generous connected kitchen diner that works properly for the way families actually live.

CBS specialises in kitchen extensions and manages every element — from the initial design through to fitting the kitchen itself. The positioning of plumbing, drainage, gas and electrics is planned at the design stage and built into the extension from the ground up. Moving these services after the walls are up costs considerably more than getting them right from the start.

The right choice if: the kitchen is the room that is not working and the household wants a single space that combines cooking, eating and relaxing — managed end to end by one team.

How to Work Out Which One You Need

Three questions cut through most of the uncertainty.

Where is the space problem? If the issue is entirely on the ground floor a single storey or kitchen extension resolves it. If the household needs both additional living space downstairs and more rooms upstairs a double storey extension addresses both with one build.

What are the budget and timeline constraints? A single storey extension costs less in absolute terms and starts sooner. A double storey extension costs more upfront but delivers a lower cost per square metre of new space — provided the household actually needs both floors.

Is a future sale part of the thinking? An open-plan kitchen diner is consistently the most sought-after feature among buyers in the Milton Keynes property market. Additional bedrooms or bathrooms from a double storey extension add measurable value at point of sale. Both investments show up in the price.

CBS Manages the Whole Project

Whichever type of extension is right for your home Crownhill Building Services handles everything from the initial site visit through to the Building Control completion certificate. Architectural services, planning applications where required, structural engineering, construction and final handover — all coordinated by one team with one point of contact throughout.

The price and all terms of the project are set out in a contract before any work begins on site.

Find Out What Is Right for Your Property

Get in touch with Crownhill Building Services today for a free no-obligation consultation. We will visit your property, assess what is possible and give you a straight recommendation — no pressure and no commitment required.

We serve Milton Keynes and surrounding areas including Bletchley, Wolverton, Newport Pagnell and beyond.