External wall insulation · London & surrounding areas

    Warmer rooms, lower heat loss, a refreshed exterior — done properly.

    Solid-wall and pre-1920s homes lose heat through their walls. Smart Renda installs external wall insulation for London homes with a real survey, a clear written quote, and no high-pressure sales, so you know exactly what is happening before work starts.

    Or call 07884 425210
    • Written, fixed-scope quote
    • Solid-wall & period-home EWI specialists (London)
    • 15-year manufacturer-backed system warranty
    The brief

    You shouldn't need a building degree to insulate your home.

    Older solid-wall homes can be hard to diagnose from the inside. These are the issues we look for before recommending any insulation or render system.

    Cold walls and rooms

    Walls feel cold to touch, rooms heat slowly, and comfort drops quickly when the heating goes off.

    Damp patches and mould

    Cold external walls can create condensation spots, especially in corners and behind furniture.

    Bills that keep climbing

    Heating runs longer because solid walls are a major heat-loss route in older homes.

    Quotes that don't match

    Different contractors price different systems, details, and scaffolding, so like-for-like comparison becomes difficult.

    What it is

    External wall insulation, in plain English.

    EWI is a continuous insulating layer fitted to the outside of the home, then finished with a weatherproof render or board system. It keeps the masonry warmer, reduces heat loss through solid walls, and can improve the exterior finish at the same time.

    Because the insulation sits outside, internal rooms keep their floor area. The important work is in the detailing around windows, sills, eaves, services, and damp courses.

    1. 01

      Insulation board fixed to the existing wall

      EPS or mineral wool boards are bonded and mechanically fixed to the existing brick, stone, or block wall outside the home.

    2. 02

      Reinforcing layer and detailing

      A reinforced base coat with mesh is detailed around windows, sills, eaves, services, and damp courses, where performance is often won or lost.

    3. 03

      Weatherproof render or finish

      Silicone, mineral, or acrylic render, or an appropriate board or brick-slip finish, protects the system and refreshes the exterior.

    SUITABILITY

    Is external wall insulation right for your home?

    External wall insulation is usually most suitable for older solid-wall homes, including many Victorian, Edwardian, and pre-1920s properties. These homes often do not have a cavity wall, so heat escapes directly through the brick or masonry.

    A proper survey checks wall condition, damp issues, access, planning context, window details, services, and the most suitable insulation and render system before any quote is given.

    Solid-wall homes

    Often found in older London properties without a cavity to insulate.

    Cold rooms and walls

    Useful where external walls feel cold, rooms heat slowly, or bills keep rising.

    Tired or failing exterior

    Can combine insulation with a fresh weatherproof render finish.

    Damp concerns

    Needs careful assessment first. EWI can help with cold-spot condensation, but it is not a shortcut over unresolved leaks or structural damp.

    Why homeowners choose it

    The changes homeowners usually notice.

    We don't promise specific savings — every property and household is different. What we can describe is what almost every customer feels after a properly specified job.

    Warmer rooms, sooner

    Walls hold heat instead of pulling it out. Rooms reach temperature faster and stay there longer.

    Less heat loss through walls

    Solid walls are a major heat-loss path on older homes. EWI directly addresses it (Energy Saving Trust).

    Reduced cold-spot dampness

    Many damp patches are caused by warm air condensing on cold walls. Warm walls = fewer cold spots.

    A refreshed exterior

    A new render finish in a colour and texture you choose — your home looks well-kept again.

    Quieter inside

    An added insulation layer also dampens road and street noise, particularly on bay walls.

    Better resilience

    Protects masonry from driving rain and weather cycles. The wall behind is doing less work.

    Source on heat loss through solid walls: Energy Saving Trust guidance on solid-wall insulation (energysavingtrust.org.uk). We don't quote specific £ savings — your surveyor will explain what results are realistic for your property.

    How a job runs

    Six steps, no surprises.

    Every project follows the same path, from a real surveyor's visit through to final inspection. You know what is being assessed, what is included, and what happens next.

    1. 01

      Free survey

      A real surveyor, not call-centre sales, visits to measure up and understand what is happening with the property.

    2. 02

      Property assessment

      Wall build-up, exposure, damp risks, planning context, access, photos, and notes are recorded.

    3. 03

      Written quote

      You receive an itemised quote covering scope, system, render type, detailing, scaffolding, and payment stages.

    4. 04

      Preparation

      Scaffolding, access, protection, and services are explained before work starts.

    5. 05

      Installation

      Boards, reinforcing mesh, render, and details are installed with a daily clean-down.

    6. 06

      Finish and aftercare

      Final inspection, sign-off, warranty paperwork, and aftercare are handled before completion.

    Why trust us

    Built for London's older solid-wall homes.

    Smart Renda is operated by Smart Building Solutions Ltd and built on practical experience in refurbishment, external finishes, property improvement, and solid-wall homes. We focus on proper assessment before recommending an EWI system, because the details around windows, sills, eaves, damp courses, services, and scaffolding often decide whether a job performs well.

    24+
    Years in the trade
    400+
    Jobs completed
    15-year
    System warranty
    Free, no-pressure
    Survey

    Smart Building Solutions Ltd, trading as Smart Renda. Companies House number 10973020.

    Clear, written quote

    Every quote spells out the system, render type, mesh, beads, scaffolding, detailing, and payment stages.

    No-pressure survey

    A surveyor explains what is possible, what needs checking, and when EWI may not be the right recommendation.

    Disruption explained upfront

    Scaffolding, access, service moves, window details, and protection are discussed before work starts.

    Solid-wall experience

    Brick, stone, render-on-block, and older wall build-ups need careful specification. We say no when EWI is wrong for the property.

    The honest answer on cost

    "What does it actually cost?"

    Anyone giving you a price over the phone is guessing. Real EWI pricing depends on a handful of measurable things — and a survey is the only honest way to put a number on them.

    • Property size and wall area. More square metres of wall = more material and labour.
    • Access and scaffold complexity. Detached and standalone is simplest. Tight terraces and rear gardens take longer.
    • Insulation thickness & system. Decided by your wall build-up, target performance, and any planning constraints.
    • Render finish & detailing. Silicone vs. mineral, plain vs. textured, plus eaves, sills, and feature detailing.
    • Existing condition. Repairs to render, brick, or pointing before insulation goes on.

    What you get from the survey

    • A walk-around with a surveyor who explains what they're seeing
    • Recommendation on system, thickness, and finish for your property
    • Honest view on planning permission and any conservation factors
    • A written, itemised quote — so you can compare like-for-like
    • Clear answer on disruption, timeline, and stages of payment
    AREAS

    External wall insulation across London and surrounding areas.

    Smart Renda works across London and surrounding areas, focusing on older solid-wall homes, Victorian terraces, Edwardian houses, semi-detached properties, and exterior refurbishments where proper detailing matters.

    North LondonEast LondonWest LondonSouth LondonGreater LondonEnfieldBarnetHaringeyWalthamstowFinchleyIslingtonHackney
    FAQ

    Questions we get every week.

    Book your survey

    One short form. One real surveyor. Zero pressure.

    Fill in the essentials and we'll be in touch within one working day to pick a survey time that suits you. If you'd rather just chat first, you can call us on 07884 425210.

    • Free, no-obligation survey
    • Written quote, valid 30 days
    • We only use your details to arrange your survey
    • No call centre, no repeated sales calls, no third-party sharing

    We use your details only to respond to this enquiry and arrange your survey. We never share your details with third parties for marketing.

    We only use your details to arrange your survey. No call centre, no repeated sales calls, no third-party sharing.

    Form for booking a free external wall insulation survey.

    Smart Renda provides external wall insulation and render finishes for older solid-wall homes across London and surrounding areas.
    © 2026 Smart Building Solutions Ltd trading as Smart Renda. Registered in England & Wales · Company no. 10973020 · Serving London and surrounding areas.