Door installation

In the UK, external door replacements are governed by specific building regulations regarding thermal performance and security. Hiring a specialist ensures these standards are met, providing peace of mind and protecting your property's value.

What Does the Work Involve?

• Site Survey: Measuring the existing opening and checking the structural integrity of the frame or lintel.
• Removal: Carefully taking down the old door leaf, hinges, and architrave without damaging the surrounding plasterwork.
• Frame Preparation: Squaring the opening, removing old fixings, and treating any damp or rot discovered in the reveals.
• Fitting: Hanging the new door, ensuring even gaps (3mm for internal) and smooth swing.
• Ironmongery: Installing handles, high-security locks (multi-point for external), letterboxes, and spyholes.
• Weatherproofing: Applying external-grade sealants, fitting weather bars, and installing draught-proofing strips.
• Finishing: Fitting new architrave, adjusting thresholds, and ensuring the door latches perfectly without forcing.

Typical Costs

Prices vary significantly based on the material (uPVC vs. Composite vs. Solid Timber) and whether the frame also needs replacing. The following 2025/26 estimates include VAT and standard labour rates.

Factors that increase the price include structural alterations to the brickwork, custom glazing requirements, and the need for scaffolding if working on a first-floor balcony or flat. Regional variations also apply, with London and the South East typically seeing 20-30% higher labour costs.

How Long Does It Take?

• Internal Door Swap: 1 to 2 hours per door (if the existing frame is reused).
• External Door & Frame: 4 to 6 hours for a standard uPVC or Composite unit.
• Bifold or French Doors: 1 to 2 days, depending on the size of the opening.
• Full House Internal Refresh (6-8 doors): 2 to 3 days for a single carpenter.

DIY or Professional?

Hanging a door is a classic "deceptively difficult" task. While a confident DIYer can trim and hang a lightweight internal door, external doors require a professional touch. External installations must comply with Part L of the Building Regulations regarding thermal heat loss.

Professional installers can provide FENSA or CERTASS certification, which is essential when selling your home to prove the door meets UK safety and energy standards.

Choosing the Right Tradesperson

• Qualifications: Look for NVQ Level 2/3 in Site Carpentry or Joinery, or FENSA/CERTASS registration for external doors.
• Red Flags: Quotes that are significantly lower than others, refusal to provide a written contract, or tradespeople who don't ask about fire safety for flat entrance doors.
• Questions to Ask:
  • Are you FENSA registered for external door installations?
  • Does the quote include all ironmongery (handles, locks, hinges)?
  • Will you dispose of the old door, and is there a waste transfer note?
  • Do you offer a guarantee on the door's alignment for the first 12 months?

UK Regulations

• Part L (Conservation of Fuel & Power): External doors must meet a minimum U-value (thermal efficiency).
• Part M (Access): Some replacement doors must maintain a minimum clear opening width for wheelchair access.
• Part Q (Security): New build doors must meet specific "PAS 24" security standards; it is highly recommended for replacements.
• Fire Safety: Doors leading to communal hallways in flats or between a garage and a house must be fire-rated (usually FD30) and fitted with a self-closing device.

Common Problems

• Binding or Sticking: Often caused by seasonal humidity changes or the door being hung before the house has "settled" after new plastering.
• Draughts: Usually the result of poor compression on the weather seals or an unlevel threshold.
• Lock Misalignment: Multi-point locks on composite doors can become difficult to engage if the frame isn't perfectly plumb.
• Dropped Hinges: Heavy solid wood or composite doors require three high-quality hinges to prevent the door from sagging over time.

Frequently Asked Questions

Do I need to replace the frame when getting a new front door?

Not always, but it is highly recommended. Modern composite and uPVC doors are designed to be "pre-hung" in their own frames for maximum security and weatherproofing. Fitting a new door into an old, warped frame often leads to draughts and security vulnerabilities.

What is the difference between a uPVC and a Composite door?

uPVC doors are made primarily of plastic and are the most budget-friendly option. Composite doors are made from a mix of materials (timber, foam, and GRP), making them thicker, stronger, more thermally efficient, and available in more realistic wood-grain finishes.

Do I need a fire door for my kitchen?

In a standard single-family home, fire doors are not typically required for kitchens. However, they are mandatory for doors leading from an integral garage into the house, and for all habitable rooms in a house with three or more storeys (loft conversions).

Why is my new door hard to lock?

This usually happens if the door or frame has shifted slightly. For composite doors, you should always "throw" the handle upwards when closing to engage the multi-point locks; this prevents the door from warping over time.

Can I just paint my uPVC door instead of replacing it?

Yes, but it requires specialist uPVC paint or "spraying." While this improves the look, it won't fix issues with draughts, security, or thermal efficiency. If the door is over 15 years old, replacement is usually a better investment.