ARB Registration (Architects Registration Board) Architectural Design, Technology and Environment Syllabus

What is the role of a vapour control layer (VCL) and on which side of the insulation is it placed in a UK building?

A VCL limits moisture-laden internal air diffusing into the construction where it could condense. In a UK (heating-dominated) climate it is placed on the warm (internal) side of the insulation.

Define the durability concept of 'frost resistance' in masonry and name the relevant UK classification letters.

Frost resistance is a brick's ability to withstand freeze-thaw cycles when saturated. UK bricks are classified F2 (frost resistant), F1 (moderately frost resistant) and F0 (not frost resistant).

What are the three soluble salt content classifications for clay bricks and why do they matter?

S2 (low salt), S1 (medium) and S0 (no requirement). Soluble salts can cause efflorescence and sulfate attack on mortar, so S2 bricks are specified in exposed/wet conditions.

Explain the difference between 'specification by description' and 'specification by performance'.

Prescriptive (descriptive) specification names exact products, materials and methods. Performance specification states required outcomes and standards, leaving the contractor to select means of compliance. Prescriptive gives control; performance allows flexibility/innovation.

What does 'fitness for purpose' mean in material specification?

It means a material or product is suitable for its intended use, location and exposure, performing its required function (structural, weathering, durability, fire, aesthetic) reliably over its design life.

What does MMC stand for and give two categories of it.

MMC = Modern Methods of Construction. Categories include volumetric (3D modular units), panelised (2D wall/floor panels), and pre-manufactured components/sub-assemblies fabricated off-site.

Compare traditional construction with off-site prefabrication in terms of speed, quality control and site disruption.

Prefabrication offers faster on-site assembly, factory-controlled quality, less waste and reduced site disruption/labour. Traditional construction is more flexible to change and design adjustment but is slower, weather-dependent and more labour-intensive on site.

What is volumetric modular construction?

A method where complete three-dimensional room-sized modules are manufactured off-site (often fully fitted out) and transported to site to be craned into position and connected together.

What is the UK's legally binding net-zero target year, and what does 'net-zero carbon' mean?

The UK is legally committed to net-zero greenhouse gas emissions by 2050. Net-zero carbon means the balance of carbon emitted equals carbon removed/offset, achieved primarily by deep reductions and minimal residual offsetting.

Distinguish 'operational carbon' from 'embodied carbon'.

Operational carbon is emitted from energy used to run a building (heating, cooling, lighting, power). Embodied carbon is emitted from materials and processes across the lifecycle: extraction, manufacture, transport, construction, maintenance and end-of-life.

What is 'whole-life carbon' and how does it relate to operational and embodied carbon?

Whole-life carbon is the sum of all embodied carbon (modules A-C, plus optional D) and operational carbon over a building's entire lifecycle, giving the total climate impact from cradle to grave.

State the core principle of passive design and name three passive strategies.

Passive design uses building form, orientation and fabric to provide comfort with minimal mechanical input. Strategies include orientation/solar gain, thermal mass, natural ventilation, daylighting, shading, and high insulation/airtightness.

Define the daylight factor and state the formula.

Daylight factor is the ratio of internal illuminance at a point to the simultaneous external horizontal illuminance under a CIE overcast sky, expressed as a percentage: $$DF = \frac{E_{\text{internal}}}{E_{\text{external}}} \times 100\%$$

What is the difference between stack (buoyancy) ventilation and cross ventilation?

Stack ventilation uses the buoyancy of warm air rising to draw cool air in low and exhaust warm air high through the temperature/height difference. Cross ventilation uses wind-driven pressure differences across openings on opposite sides of a space.

What is thermal mass and how does it improve comfort?

Thermal mass is a material's capacity to absorb, store and release heat (e.g. concrete, masonry). It dampens temperature swings by absorbing daytime heat and releasing it at night, stabilising internal temperatures and reducing peak loads.

Name three low-carbon building services systems used to decarbonise heating.

Air-source and ground-source heat pumps, heat recovery ventilation (MVHR), connection to low-carbon district heat networks, solar thermal, and PV with electrification of heat.

How does a heat pump's coefficient of performance (COP) make it efficient, and what does a COP of 3 mean?

COP is the ratio of useful heat output to electrical energy input: $COP = \frac{Q_{\text{heat}}}{W_{\text{electric}}}$. A COP of 3 means 3 units of heat are delivered per 1 unit of electricity, by moving heat rather than generating it.

What does MVHR stand for and what does it do?

MVHR = Mechanical Ventilation with Heat Recovery. It supplies fresh air and extracts stale air while a heat exchanger transfers heat from the outgoing to the incoming air, reducing ventilation heat loss in airtight buildings.

What is BREEAM and what are its rating levels?

BREEAM (Building Research Establishment Environmental Assessment Method) is a UK sustainability assessment scheme rating performance across categories. Ratings are: Pass, Good, Very Good, Excellent, and Outstanding (plus Unclassified/Acceptable).

State the key Passivhaus performance criteria.

Space heating demand $\leq 15\,\text{kWh/m}^2\text{a}$ (or heating load $\leq 10\,\text{W/m}^2$); airtightness $\leq 0.6\,\text{ach}$ at 50 Pa; and primary energy demand within prescribed limits, with high comfort and no overheating.

What are the headline operational energy and embodied carbon goals of the RIBA 2030 Climate Challenge?

By 2030 the RIBA targets for example operational energy below $\sim 55\,\text{kWh/m}^2\text{a}$ (non-domestic) / $35\,\text{kWh/m}^2\text{a}$ (domestic), embodied carbon below $\sim 625\,\text{kgCO}_2\text{e/m}^2$, and a major cut in potable water use.

Define 'retrofit' and distinguish shallow from deep retrofit.

Retrofit is upgrading an existing building's fabric and services to improve performance. Shallow retrofit makes incremental improvements (e.g. lighting, draught-proofing); deep retrofit comprehensively upgrades fabric, airtightness and services to near-zero-carbon standards.

Explain the 'circular economy' principle as applied to buildings.

A circular economy keeps materials in use at their highest value, designing out waste through reuse, repair, refurbishment, remanufacture and recycling, e.g. designing for disassembly and adaptability rather than demolition (a 'take-make-dispose' linear model).

What is 'design for disassembly (DfD)' and why does it matter for the circular economy?

DfD is designing connections and components so a building can be taken apart at end-of-life, allowing materials and parts to be reused or recycled cleanly rather than downcycled or landfilled. It maximises future material value.

In drawing conventions, what scales are conventionally used for a location plan, general arrangement plan, and detail?

Location/site plans at $1{:}500$ or $1{:}1250$; general arrangement plans/sections/elevations at $1{:}50$ or $1{:}100$; details at $1{:}5$, $1{:}10$ or $1{:}20$ (full size $1{:}1$ for components).

What is 'production information' in the RIBA Plan of Work and at which stage is it primarily produced?

Production information is the detailed drawings, specifications and schedules that allow a building to be constructed. It is primarily produced in Stage 4 (Technical Design).

What is the NBS and what is its role in specification?

NBS (National Building Specification) is a UK system providing standardised, regularly updated specification clauses and libraries. It helps architects write consistent, coordinated, compliant specifications linked to drawings and BIM objects.

What is BIM and what does ISO 19650 govern?

BIM (Building Information Modelling) is the collaborative creation and management of digital information about a built asset. ISO 19650 is the international standard for organising and managing information using BIM across a project's whole life cycle.

In ISO 19650, what is the CDE and what are its four states of information?

The CDE (Common Data Environment) is the single agreed source of project information. Its information states are: Work in Progress (WIP), Shared, Published, and Archived.

Why is coordination of design information across disciplines essential, and name a BIM technique used to achieve it.

Coordination ensures architectural, structural and services (MEP) information align without conflicts, preventing errors, rework and cost overruns on site. Clash detection in a federated BIM model is used to find and resolve spatial conflicts before construction.