London's Prestige
Renovation Glossary
Plain English explanations of the terms you will meet when planning a renovation, loft conversion or extension in London. Written by the team that manages these projects from start to finish.
A
- What Is an Article 4 Direction? How It Restricts Permitted Development
An Article 4 direction is an order made by a local council that removes specific permitted development rights in a defined area.…
B
- Building Control Sign Off Explained: The Final Step Before Completion
Building control sign off is the final approval confirming that building work complies with the Building Regulations. After a final inspection, building…
- What Is Building Regulations Approval (and How Is It Different From Planning Permission)?
Building regulations approval confirms that building work meets national standards for structure, fire safety, insulation, drainage, ventilation and access. It is separate…
C
- Category A vs Category B Fit Outs Explained
A Category A fit out turns a shell into a basic, usable space with raised floors, ceilings, lighting, heating, cooling and toilets.…
- What Is “Change of Use” and When Does It Apply to Your Property?
Change of use is when a property starts being used for a different purpose that falls into another planning use class, such…
- What Is a Commercial Fit Out?
A commercial fit out is the process of making an internal space ready for a business to occupy, such as an office,…
D
- Double Storey Extensions Explained: Cost, Planning and Structure
A double storey extension adds space on two floors at once, typically a larger kitchen or living area downstairs and an extra…
- What Are Dilapidations? What Commercial Tenants Need to Know
Dilapidations are the breaches of a commercial lease's repair, decoration and reinstatement obligations, and the landlord's claim to have them put right.…
- What Is a Dormer Loft Conversion?
A dormer loft conversion extends the roof with a box shaped structure that has vertical walls and a flat or shallow roof,…
F
- Fire Compartmentation Explained: A Commercial Renovation Essential
Fire compartmentation is the division of a building into sections enclosed by fire resisting walls, floors and doors, so a fire is…
- First Fix vs Second Fix: What Happens at Each Stage of a Build
First fix is the stage where services and structure that will be hidden are installed: pipework, cables, back boxes, studwork and door…
- Full Planning Permission Explained: When You Need It
Full planning permission is formal approval from your local council for building work or a change of use that falls outside permitted…
H
- Hip to Gable Conversions Explained: Is Your Roof Right for One?
A hip to gable loft conversion replaces the sloping side (the hip) of a roof with a vertical wall (a gable), extending…
K
- Kitchen Islands Explained: Layout, Space and Planning Considerations
A kitchen island is a freestanding run of units in the middle of a kitchen, open on all sides, that adds worktop,…
L
- Listed Building Consent Explained: Renovating a Protected Property
Listed building consent is permission from your local council to alter, extend or demolish any part of a listed building in a…
- Load Bearing Walls Explained: How to Tell If a Wall Can Be Removed
A load bearing wall carries weight from the structure above, such as floors, other walls or the roof, down to the foundations.…
M
- Mansard Roofs Explained: The Loft Conversion for Period Properties
A mansard loft conversion replaces the roof slope with a near vertical wall, typically around 70 degrees, topped by a flat roof,…
- What Counts as “Means of Escape” in a Commercial Refurbishment?
Means of escape is the route people use to leave a building safely in a fire, from any point inside to a…
P
- Permitted Development Rights Explained: What You Can Build Without Planning Permission
Permitted development rights allow certain building work on houses in England without a planning application, such as some rear extensions, loft conversions…
- Provisional Sums Explained: Why Your Quote Isn’t Always Fixed
A provisional sum is an allowance included in a building quote for work or items that cannot yet be priced exactly, such…
- What Does a Party Wall Surveyor Actually Do?
A party wall surveyor administers the Party Wall etc. Act 1996 when building work affects a shared wall or neighbouring foundations. They…
- What Is a Party Wall Agreement and When Do You Need One?
A party wall agreement is the everyday name for the process under the Party Wall etc. Act 1996, where you serve notice…
R
- Roof Lights vs Velux Windows: What’s the Difference?
A roof light is any window fitted into a roof to bring in daylight. Velux is a well known brand of pitched…
- RSJs Explained: What a Steel Beam Does in Your Renovation
An RSJ steel beam (rolled steel joist) is used to carry the weight of the structure above when part of a load…
- What Is Retention in a Building Contract?
Retention in a building contract is a small percentage of each payment, held back by the client as security against defects. Part…
S
- Single Storey Extensions Explained: What’s Involved
A single storey extension adds ground floor space to a house, usually at the rear, into a side return or as a…
- Snagging List Explained: What It Is and Why It Matters at Handover
A snagging list is a written record of small defects and unfinished details found when a building project is inspected near completion.…
- What Is a Schedule of Works? A Guide for Renovation Clients
A schedule of works is a written list of every task in a building project, room by room or trade by trade,…
- What Is a Structural Opening? Removing Walls Safely in a Renovation
A structural opening is a new or enlarged gap in a load bearing wall, such as knocking through a kitchen and dining…
U
- What Is a Utility Room and Do You Need One?
A utility room is a separate space for laundry and household tasks, usually housing the washing machine, tumble dryer, a sink and…