Listed Security CEO Design Service Book · £1,200
Pencil study of a Georgian sash window set within a brick façade
Heritage Security Assessment · Central London

Protection,
by consent.

A principal-led security assessment for Grade I, II* and II listed buildings and conservation-area homes — written to satisfy the insurer, the security consultant and the conservation officer in a single document.

Security advice for listed buildings is usually written by people who have never secured a consent. Heritage advice is usually written by people who have never specified a doorset that has survived a breach test. This assessment is where the two disciplines meet: one survey, one document, and a clear route from threat to consented installation.

£1,200
Fixed and capped
£600 secures your survey date
Book the assessment → Read the method
Small  |  Batch  |  Bespoke
National Policy Current
NPPF 2026, Chapter 20 — in force since 17 August 2026. Every assessment is framed against Policies HE4–HE6 and HE9, the new effects-based tests for designated heritage assets and conservation areas.
Statute
Planning (Listed Buildings and Conservation Areas) Act 1990 — s.7 consent for works affecting character; s.16(2) and s.66(1) special regard; s.72 conservation areas.
Historic England
Statements of Heritage Significance, HEAN 12 (2019) · Traditional Windows: their care, repair and upgrading (2017) · Conservation Principles (2008).
Performance
BS EN 1627 resistance class RC4 · BS EN 1522 bullet resistance FB4 · LPS 1175 · PAS 24:2022 — engineered with our manufacturing partner, FORT.
The Commission

What £1,200 commissions

Six deliverables. One visit. A document that can be handed to an insurer, a contractor or a conservation officer without translation.

01

Principal-led survey

Conducted on site by the practice principal, never delegated. Every opening, approach, lightwell and boundary recorded — photographed, measured and read against the list entry.

02

Statement of significance

Prepared on the Historic England HEAN 12 approach: what matters about the building, where that significance resides, and which fabric can accept intervention. The foundation of every consent that follows.

03

Threat & risk assessment

A bespoke reading of exposure — approach routes, sight lines, vulnerable openings, occupancy patterns and the insurer's position — calibrated to the household, not a template.

04

Anti-intrusion specification

RC-rated doorsets, secondary and bullet-resistant glazing, access control and concealed detection, specified with indicative pricing through our manufacturing partner FORT.

05

Collection security

Recommendations for art, antiques and collections: the rooms that hold them, display and hanging, environmental risk and the protection of what cannot be replaced.

06

Consent route

A planning and Listed Building Consent outline under the 1990 Act and NPPF 2026 Chapter 20 — what needs consent, what does not, and the strategy most likely to secure it.

Technical Methodology

The art of
careful removal

Security in a listed building is decided long before the new door arrives. It is decided by what is taken out, how the opening is read, and whether the historic fabric is left exactly as it was found.

This is the discipline the assessment is written to, and the standard every CEO Design Service installation is held to on site. It is set out here in full, because the method is the proof.

Drawn from our site methodology for recent interventions at Grade listed projects in central London
  1. 01Pre-removal survey & conditionPhase one
  2. 02Controlled extractionPhase two
  3. 03Opening inspection & defectsPhase three
  4. 04Preparation & installationPhase four
Phase One

Pre-removal survey &
condition assessment

No joinery element is removed on any CEO Design Service heritage commission without a comprehensive survey conducted in advance of works. This is not procedural formality. It is the discipline that separates conservation-grade installation from standard contractor practice.

The survey establishes the precise significance of the element to be removed. Where original fabric is present — however compromised — its removal requires documented justification and the prior grant of Listed Building Consent.

Across recent interventions at Grade listed projects in central London, archival research has repeatedly shown that doors and screens assumed to be original were later insertions. Confirmed with the conservation officer, a finding of that kind reframes a project entirely: the removal of a modern intrusion and its replacement with a period-accurate, heritage-enhancing installation.

  • Photographic record of every existing element in situ
  • Measured survey of opening dimensions and any deviation from original drawings
  • Condition assessment of frame, reveal, threshold and lintel
  • Identification of concealed fixings, cables or services within the opening depth
  • Written statement of significance to accompany the consent submission

"Significance is established before intervention is contemplated — never reconstructed afterwards to justify it."

CEO Design Service — Heritage Integration Methodology
Pencil study of a surveyor working at a historic door opening beneath a fanlight
Pre-removal survey — recording the opening and its condition in situ
Consent before removal

The order of works is not negotiable

Under s.7 of the 1990 Act and the heritage policies of each borough's local plan, removing any element that forms part of a listed building — even a modern insertion — can require Listed Building Consent where it affects character.

  • Consent granted before any removal commences
  • Pre-application dialogue with the conservation officer as standard
  • Removal photography forms part of the consented works record
  • Practice principal on site throughout extraction
Phase Two

Controlled extraction —
frame, sash & door

Extraction is calibrated to the element, its condition, the surrounding construction and the fixings employed. There is no universal method — which is precisely where conservation practice parts company with building maintenance.

Door leaves are de-hung partially open to relieve stress on the frame. Hinges are unscrewed, never levered, and the leaf is supported by a second operative throughout. Architrave paint bond is checked before anything moves.

Frames are the more demanding operation. Original lime mortar beds are friable and release with careful chiselling. Later Portland cement repairs are harder and call for an oscillating tool rather than hammer and chisel, so that no percussive shock reaches the masonry. Every fixing is located before a single cut is made.

Sash windows are treated as assemblies, never dismantled in position. Weights, cords, pulleys and beads are retained. All original ironmongery, however worn, is catalogued and photographed, and significant pieces are proposed for reuse within the new installation — the material continuity conservation officers value.

Removed material is lowered, never dropped, and leaves site wrapped. Historic timber is handled as potentially significant material; modern fixings are separated and disposed of conventionally.

Pencil study of an extracted historic timber section showing weathered end grain
Extracted section — historic timber handled as potentially significant material
  1. 01

    Temporary protection

    Floors, cornices, dados and plaster reveals protected with soft-edge masking. No tape on painted finishes without a release layer.

  2. 02

    Hardware catalogue

    Ironmongery unscrewed, labelled and photographed by location. Retained pieces refurbished for reinstatement.

  3. 03

    Leaf de-hanging

    Leaf supported before hinge screws are drawn, lifted clear of the threshold and moved straight to flat protected storage.

  4. 04

    Frame release

    Cut at head and jamb junctions with an oscillating tool. The bed released progressively — never levered — to avoid spalling.

  5. 05

    Extraction

    Sections lowered to floor level, proud fixings drawn over a timber pad, opening brushed clean and photographed in its cleared state.

Pencil study of an engineered security frame with multi-point locking being carried into position
The engineered chassis — multi-point security concealed within a period-accurate case
Pencil study of a brass sash fastener on a painted meeting rail
Period hardware — catalogued before removal, refurbished for reinstatement
Phase Three

The structural opening —
inspection & defects

Once the frame is out, the structural opening is exposed — frequently for the first time in decades. What is found here decides the quality and longevity of everything that follows. No new frame is offered in until inspection is complete and every defect remediated.

Four zones are examined: the lintel or arch; the jamb reveals; the threshold sill; and the cavity behind the former frame rebate. In Victorian and Edwardian construction, lintels are typically stone or brick arch. Any deflection is recorded and referred to a structural engineer. Active cracking, spalling or movement is a hold point.

Reveals are checked for friable mortar, earlier hacking-out, unsound render and embedded services. Services are re-routed, never simply enclosed within the new frame — the installation is designed to be reversible, with no concealed dependency.

Lintel

Deflection, cracking and bearing. Stone checked for delamination and old patch repairs; brick arch soffits for joint failure.

Reveals

Joints raked and assessed. Previous hacking-out recorded. Faces clean, sound and free of loose material before the frame is offered in.

Threshold & sill

Slope, saturation and patching checked. Water ingress resolved first. Visible threshold details agreed with the conservation officer.

Services & cavities

Concealed wiring, moisture and old insulation identified. All electrical and alarm cabling formally re-routed. Depth confirmed against the new frame.

Pencil study of hands examining the letterplate of a panelled front door
Inspection — reading the opening and its ironmongery post-extraction
Hold points

When installation must pause

Four conditions suspend installation until professional assessment or remediation is complete:

  • Active movement in lintel or arch — structural engineer before proceeding
  • Rising or penetrating damp within the reveal — specialist survey
  • Previously unknown concealed services — M&E re-routing certificate
  • Evidence of historic fire or flood damage — full fabric investigation
Phase Four

Opening preparation &
new frame installation

A poorly prepared opening will compromise even the highest-specification RC4 / FB4 doorset. Five criteria are met before the new frame is offered in:

  • Dimensional accuracy — within ±3mm of survey dimensions
  • Structural integrity — sound joints; any repairs fully cured
  • Surface cleanliness — dust, loose material and efflorescence removed
  • Moisture — masonry below 6% moisture content by calibrated meter
  • Level and plumb — threshold and jambs within FORT's installation tolerances

The FORT security frame sits within the existing structural opening. No cutting, hacking or enlargement of the historic aperture is required or permitted. It is a central tenet of the method and a condition we build into every consent: the installation is reversible, the opening unaltered.

Frames are fixed with stainless steel anchors to the masonry reveals, never to the former rebate. On lime-mortared masonry, a lime-compatible, breathable sealant is specified in place of silicone, which traps moisture in traditional construction. The frame-to-reveal junction is finished with a lime putty stopping, matched to the existing reveal and indistinguishable from it.

The leaf is hung only once the frame is confirmed level, plumb and fully fixed. Locks, hinges and access control are installed to manufacturer's specification and tested before sign-off. A final photographic record is taken from the same positions as the pre-removal survey — a complete before-and-after file for the conservation officer.

"The goal is an installation that a conservation officer — or a future historian — would examine and conclude was always there."

CEO Design Service — Heritage Integration Methodology
The reversibility principle

Removable without trace

Every security intervention is designed so it can be taken out without damage to historic fabric. That principle governs the whole method — the choice of fixings, the choice of sealant, the design of the frame-to-reveal junction — and it is the principle that carries a consent through committee.

Under NPPF 2026

Harm, or positive effect

Chapter 20 has retired "less than substantial harm". Effects on significance are now read as positive, neutral, harm, substantial harm or total loss, and Policy HE6 supports proposals with positive effects. Removing a modern intrusion and reinstating a period-accurate element is written to be read as a positive effect.

From booking to document

Five steps, one principal

  1. i

    Brief

    Complete the booking brief below. You receive a booking reference immediately.

  2. ii

    Deposit

    £600 through Stripe secure checkout. Your preferred survey windows are held.

  3. iii

    Confirmation

    The studio confirms your survey date and access arrangements within one working day. From confirmation, the deposit is non-refundable.

  4. iv

    Survey

    The practice principal on site, by appointment, with the discretion the property requires.

  5. v

    Document

    Balance of £600 on your approval following survey. The final assessment is released on receipt.

Scope

For whom, and where

Deliberately narrow. The practice works in a small batch of prime central London properties each year, and the assessment is priced for that geography alone.

Properties

  • Grade I & II* listedHistoric England a statutory consultee on most works
  • Grade II listedTownhouses, mansion flats, mews and villas
  • Conservation areasIncluding properties subject to Article 4 Directions
  • Institutional & places of worshipWhere public access and protection must coexist

Commissioned by

  • Private ownersPrincipal residences and London houses
  • Family officesActing for UHNW principals
  • Estate & property managersWithin landed estate consent frameworks
  • Architects & agentsSeeking specialist security input to a wider scheme

Boroughs

  • City of WestminsterMayfair · Belgravia · Marylebone · St James's
  • Kensington & ChelseaKensington · Chelsea · Knightsbridge · Holland Park
  • Camden & the CityBloomsbury · Hampstead · City of London
  • Hammersmith & FulhamBy arrangement
Case law in view

Decision-makers must give considerable importance and weight to the desirability of preserving a listed building and its setting — Barnwell Manor Wind Energy Ltd v East Northamptonshire DC [2014] EWCA Civ 137. Every assessment is written with that statutory duty, and the officer who must discharge it, in mind.

Booking

Book the
assessment

Four short steps. Your brief reaches the studio, your deposit secures the date, and the principal prepares for the visit before arriving.

  • Fee£1,200 fixed and capped. £600 today, £600 on your approval following survey. No VAT is charged.
  • DepositReturned in full if you cancel before your survey date is confirmed; non-refundable thereafter. Booking terms
  • PaymentStripe secure checkout. Card details never reach this site.
  • ResponseSurvey date confirmed within one working day of your deposit.
  • DiscretionProperty details, photography and specification held in strict confidence and never used without written consent.
  • Directstudio@ceodesignservice.com
  1. iProperty
  2. iiSurvey
  3. iiiContact
  4. ivConfirm
The property

What the principal needs to know before arriving.

Primary concerns — select any
Survey windows

Choose up to three preferred windows. The studio confirms one within a working day of your deposit.

Preferred windows
0 of 3 selected
Your details

Held in confidence and used only to arrange your assessment.

Confirm & secure

Review your brief, then secure your survey date with the £600 deposit.

Booking reference
—
Quote on all correspondence
Heritage Security Assessment — fixed and capped£1,200
Balance on your approval following survey£600
Deposit due today — non-refundable once your date is confirmed£600
First — send your brief to the studio
Send brief to the studio
Then — secure your survey date
Secure your date — £600 deposit →

No VAT is charged: CEO Design Service (UK) Ltd is not currently VAT registered. Payment is taken by Stripe; card details never reach this site. Your booking reference is attached to your deposit so the studio can match it to your brief. Prefer to speak first? Write to studio@ceodesignservice.com.

Questions

Asked before booking

Is the £1,200 fee genuinely capped?
Yes. £1,200 is the total fee for the assessment of a single property in central London — no hourly extensions, no survey supplements and no VAT. £600 secures your survey date; the £600 balance falls due on your approval following survey, and the final document is released on receipt.
Is the deposit refundable?
Until the studio confirms your survey date, yes — cancel and the £600 is returned in full. Once your date is confirmed, the deposit is non-refundable, as that date is reserved exclusively for your property.
Who carries out the survey?
The practice principal, in person. The survey is never delegated, because the reading of the building on the day is what the whole document rests on.
Will the recommended works need Listed Building Consent?
Often, yes. Section 7 of the 1990 Act requires consent for any works that affect the character of a listed building as a building of special architectural or historic interest. Replacement doorsets, glazing, fixed detection and access control frequently fall within that test. The assessment identifies precisely which elements need consent, which do not, and the strategy most likely to secure approval under NPPF 2026 Chapter 20.
My property is not listed, but it is in a conservation area. Is the assessment relevant?
Yes. Article 4 Directions can remove permitted development rights, and external security works in conservation areas frequently require planning permission. Decisions are governed by NPPF 2026 Policy HE9 and s.72 of the 1990 Act. The assessment addresses both.
What happens after the assessment?
The document is yours to use as you see fit — with your insurer, your contractor or another adviser. Where you would like the practice to take the work forward, consent, specification and installation with FORT are proposed separately, on the same small-batch basis.
How is confidentiality handled?
Property details, photography and specifications are held in strict confidence. Nothing relating to your property is published or shared without your written consent.
Booking terms

Plainly stated

  1. The serviceA Heritage Security Assessment of a single property in central London, surveyed in person by the practice principal of CEO Design Service (UK) Ltd.
  2. The fee£1,200, fixed and capped. No VAT is charged: CEO Design Service (UK) Ltd is not currently VAT registered.
  3. The deposit£600, paid through Stripe at booking. It holds your preferred survey windows while the studio confirms your date, normally within one working day.
  4. Before confirmationYou may cancel at any time before your survey date is confirmed, and the deposit is returned in full.
  5. After confirmationOnce your survey date is confirmed, the deposit is non-refundable, as that date is reserved exclusively for your property.
  6. The balance£600, due on your approval following survey. The final assessment is released on receipt.
  7. Early startWhere your confirmed survey date falls within 14 days of booking, you request that the service begins within the cancellation period under the Consumer Contracts (Information, Cancellation and Additional Charges) Regulations 2013.
  8. ConfidentialityProperty details, photography and specifications are held in strict confidence and never published or shared without your written consent.