Loft Conversion Cost in Eltham (2025)
Prices, Planning Rules & How to Choose the Right Builder

Eltham (SE9) is one of South East London's most desirable residential areas, known for its mix of period terraces, 1930s semis, and modern family homes. With landmarks like Eltham Palace, Oxleas Woods, and the busy Eltham High Street, the area blends green surroundings with excellent transport links to central London. Many Eltham homes have unused roof space that can be transformed into bright bedrooms, home offices, or en-suites, making loft conversions one of the most popular improvements for growing families.

Running out of room in Eltham? A well-designed loft conversion can add living space and significant value, without the disruption of moving. This Eltham-specific guide provides accurate 2025 price ranges, explains what's included, what drives costs, planning rules and building regulations, realistic timelines, ROI potential, and practical tips on choosing the right builder.

How much does a loft conversion cost in Eltham?

Pricing below reflects SE London / Eltham market rates for 2025 (labour + materials), including insulation, structural work, and a compliant finish.

Add-ons to budget for:

• En-suite fit-out: £4,000 – £8,000+
• Juliet balcony / feature glazing: £2,000 – £6,000+
• Bespoke staircase & joinery: £1,500 – £4,000+

What's included in those prices (and what isn't)

Included:

• Survey, structural calculations, Building Control liaison
• Steels, joists, structural floor
• Roof alterations (Velux, dormer, hip-to-gable, mansard)
• Insulation to Part L standards
• Fire safety (alarms, FD30 doors, escape windows)
• Electrics and heating tie-in
• Plaster/skim and basic joinery
• Standard staircase to Part K compliance
• Building Control inspections and completion certificate

Exclusions:

• Bathroom sanitaryware and tiling
• High-end finishes (stone tops, crittall glazing, bespoke wardrobes)
• Planning application and Party Wall surveyor fees
• Full re-roofing beyond loft scope
• Decorating beyond basic paint

What drives loft conversion cost up — or down

Factors that increase costs:

• Larger or more complex roof types (mansard vs Velux)
• Steelwork in older terraced homes
• Bespoke staircase layouts
• En-suite bathrooms with plumbing upgrades
• Juliet balconies or large glazing units
• Conservation requirements (e.g. areas near Eltham Palace or Progress Estate)
• Difficult site access or parking

Ways to control costs:

• Use Permitted Development rights where possible
• Stack plumbing above existing bathrooms
• Keep staircase layouts simple
• Invest in mid-range finishes, upgrade visible fittings

Planning permission & building regulations in Eltham

• Permitted Development (PD): Many Velux and rear dormers in Eltham qualify under PD, subject to volume and setback restrictions.
• Planning permission: Needed for mansards, front dormers, or homes near conservation areas like the Progress Estate or around Eltham Palace.
• Party Wall etc. Act 1996: Applies to most terraces and semis in SE9; budget £1,000–£2,000+ per affected neighbour.

Building Regulations:

• Part A – structure/steels
• Part B – fire safety (alarms, fire doors, escape windows)
• Part K – staircase pitch and guarding
• Part L – insulation/thermal performance
• Part P – electrics certification
• Ventilation – extractor fans for wet rooms

Timeline: how long does a loft conversion take?

• Pre-construction: 3–8 weeks
• Velux build: 4–6 weeks
• Rear Dormer: 6–8 weeks
• Hip-to-Gable or Mansard: 8–12+ weeks
• Snagging and sign-off: 1–2 weeks

ROI: how much value can a loft conversion add in Eltham?

A loft conversion typically adds 10–20% to property value. With house prices strong in SE9, particularly around Eltham Park, New Eltham, and Avery Hill, a compliant bedroom and en-suite can deliver one of the best returns on investment compared with ground-floor extensions.

How to choose the right loft conversion company in Eltham

• End-to-end capability: design, structure, build, finishing
• Transparent scope: clear allowances and PC Sums
• Compliance pedigree: Building Control approvals, Part P certification, fire safety strategy
• Warranty: 18-month workmanship warranty with Buildaway
• Local expertise: completed lofts in SE9 across Eltham Park, New Eltham, and Mottingham borders
• Practical site planning: experience working on Eltham's suburban roads and conservation-sensitive areas

Budget-smart tips (without cutting corners)

• Plan headroom early for Eltham's hipped-roof semis
• Design staircase layouts upfront
• Stack bathrooms/en-suites over existing plumbing
• Spend on insulation/airtightness for comfort and efficiency
• Upgrade only visible elements like lighting, doors, and brassware

Example Buildaway packages (guide pricing)

• Velux Room-in-Roof — £27,500–£34,500
  Includes structural floor, rooflights, insulation to regs, staircase, electrics/heating, plaster finish. En-suite prep optional.
• Rear Dormer + En-suite Ready — £42,000–£56,000
  Includes dormer structure, staircase, insulation, M&E, plaster finish. En-suite fit-out typically +£4,000–£8,000.
• Hip-to-Gable with Rear Dormer — £54,000–£68,000
  Includes hip-to-gable extension, dormer, steels, staircase, full compliance, ready-to-decorate.

(All guide prices include labour, main materials, waste removal, and Building Control. Final quotes depend on survey, access, and specification.)

FAQs (Eltham)

Why Eltham homeowners choose Buildaway