Security systems retrofitted into a finished house are always a compromise. Here is how to integrate security correctly from the outset of a renovation.
Security is the element of a residential renovation most commonly specified too late. The cameras go in after decoration; the alarm is added by a separate contractor at the end; the access control is an afterthought. The result is a system that works but shows — surface-mounted cable runs, cameras on visible brackets, keypads at odd heights — and often one that is not integrated with the rest of the building.
In a high-specification renovation, security should be designed as part of the building from the first-fix stage. Here is how to approach it.
The four components of residential security
Perimeter control: Physical measures to prevent or deter entry — locks, doors, windows, gates, fencing, lighting. The first and most important layer. No electronic system compensates for inadequate physical security.
Intrusion detection: Alarm systems — PIR detectors, door and window contacts, glass break detectors, vibration sensors — that detect an intrusion after it has occurred and trigger an alarm response.
Access control: Systems that manage who can enter the property — smart locks, keypads, fob readers, video intercoms, automated gates. Can be standalone or integrated with the building management system.
CCTV and monitoring: Camera systems for both deterrence and post-event recording. Can be monitored locally (NVR/DVR), remotely (cloud), or by a professional monitoring station.
A properly designed system addresses all four layers. An alarm system without adequate physical security, or cameras without a recording system, are each partial solutions.
Perimeter security: the physical layer
Doors: The front door of a high-specification London townhouse should be specified to PAS 24 as a minimum (the standard required by Secured by Design, the police-backed security initiative). This means a multi-point locking system (typically three points — top, bottom, and central latch), a tested cylinder resistant to snapping and picking, and a tested frame and hinges resistant to attack. Many high-end front doors are certified to the higher RC2 European resistance class.
Windows: Ground floor and easily accessible upper floor windows should have window locks and, if laminated glass is not specified throughout, security film (a retrofit option for existing glass). Timber sash windows in period properties are a security vulnerability that is worth addressing — security sash stops, sash locks, and reinforced glass are the standard mitigations.
Roof terraces and lightwells: Access points that are not doors and windows — roof terrace access from adjacent roofs, lightwell access from below — are commonly overlooked. A security audit of the property as part of the design process should identify these.
First-fix infrastructure: the irreversible decisions
The second-fix security installation is constrained by what was done at first fix. If cables were not run, if conduit was not installed, if power was not provided at the right locations — the options are limited to surface-mounted solutions or expensive reinstatement.
At first fix, the security specification should determine:
Cable routes: CCTV cameras require data cable (typically Cat6 for IP cameras) and power (or PoE — power over ethernet). Alarm sensors require two-core or four-core alarm cable. Access control devices require data and power. All cables should be run in conduit where they pass through walls or floors, allowing future replacement.
Camera positions: Camera positions should be designed (or at least marked and cabled for) before plastering. External cameras require weatherproof boxes and appropriate IP ratings (IP66 minimum); internal cameras require clean cable management to the NVR location.
Alarm panel and detection devices: The alarm panel should be in a secure, accessible location (typically a plant room or utility area). PIR detector positions should be agreed with the alarm installer before boarding and plastering — the ideal position for a detector is not always the same as where it is easiest to install after the fact.
Intercom and gate systems: Video intercom cables (for door station and internal monitors) and gate control cables should be run at first fix. Gate motors and control systems may require mains power that needs to be provided during groundworks.
Alarm systems: grades and monitoring
UK alarm systems are classified by grade (1–4 under EN 50131) and by whether they are monitored or self-contained:
Grade 2 is the standard for domestic installations. It uses dual-technology detectors (PIR plus microwave or ultrasonic), door/window contacts, and sirens. A Grade 2 system with professional monitoring (through a monitoring station connected by the alarm system's GPRS and telephone backup) is the appropriate specification for a high-value London property.
Monitoring: A professionally monitored alarm system connects to a 24-hour monitoring station when activated. The station verifies the alarm (typically by video verification or voice challenge) and dispatches police, key holder, or response unit as required. This transforms an alarm from a noise-making device into an active security response.
Police response: Police in London maintain the right to refuse response to repeat false alarms. A property with a history of false alarm activations may be removed from the police response list. This is another reason for quality installation and commissioning — poorly installed systems with false alarm problems are a security liability.
CCTV specification
Resolution: Modern IP cameras at 4MP or above provide facial and vehicle recognition quality at normal viewing distances. 2MP (1080p) is a practical minimum for most positions.
Field of view: Wide-angle lenses (2–4mm) for entrances and large spaces; standard lenses (6–12mm) for longer focal lengths (gates, driveways). The camera specification should be matched to the field of view requirement, not just generic positioning.
Night vision: IR illumination is standard in most IP cameras, but the quality varies enormously. Cameras with built-in IR are adequate for most positions. For critical positions (main entrance, garage), a camera with good low-light sensitivity (Sony Starvis or equivalent sensor) outperforms an IR-illuminated camera in real-world conditions.
Storage: The NVR (network video recorder) should provide a minimum of 30 days of continuous recording for all cameras, at full resolution. Storage sizing should be calculated for the specific camera count and resolution. Cloud storage as a supplement (not a replacement) to local storage provides resilience against theft of the recording device.
Access: The CCTV system should be accessible remotely — via smartphone app — so the owner can review footage and check live cameras from anywhere.
Smart locks and access control
Smart locks — which replace or supplement the physical key — are increasingly specified in high-end London renovations. The options:
Smart cylinders: A retrofit cylinder (such as Nuki, Danalock, or the Mul-T-Lock range) that replaces the existing cylinder and adds Bluetooth/Wi-Fi connectivity. Allows keypad, fob, smartphone, or code access alongside the physical key. Practical for existing doors; does not require wiring.
Integrated smart locks: Lock sets designed from the ground up for keyless access — typically more architecturally resolved than retrofit solutions. Often integrated with the wider home automation system.
Video intercoms: A video intercom at the front door — allowing the occupant to see and speak to callers via smartphone from anywhere — is standard in high-specification London renovations. The door station should be specified consistently with the property's architectural aesthetic; many manufacturers offer stainless, brass, and black finishes in minimal formats.
Integration with home automation
In a whole-house renovation with a home automation system (Crestron, Control4, KNX, or similar), security integration adds significant value:
- —CCTV feeds viewable on in-room screens and mobile devices
- —Alarm arm/disarm from the app or in-room keypads
- —Gate and intercom answering from any screen in the house
- —Automated responses: lights on at perimeter when alarm is triggered; cameras record when gate opens
Integration requires the security systems to be specified as compatible with the chosen automation platform from the outset. Retrofitting integration after the fact is always more difficult.
Budget guidance
| Scope | Indicative cost |
|---|---|
| Grade 2 alarm, professional monitoring, basic CCTV (8 cameras) | £8,000–15,000 |
| Full residential security: alarm, 16-camera CCTV, smart access, intercom | £20,000–45,000 |
| Integrated security with home automation, premium specification | £45,000–100,000+ |
ASAAN's approach
ASAAN coordinates security specification and installation as part of the whole renovation programme. We ensure cabling infrastructure is installed at first fix to the correct specification for the chosen security systems, and manage the security installer as a specialist subcontractor.
If you are planning a renovation where security is a priority, contact us to discuss specification.
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