Termite Protection Requirements: NCC 2025 Part 3.4, AS 3660.1, Slab Edge Exposure, Subfloor Clearance and the Durable Notice (2025 Guide)

Many new houses in Australia need a termite management system, but not all of them, and the reason is written into the National Construction Code (NCC). The test has two parts. Is the site in an area where subterranean termites are a known risk? And is any primary building element made of a material the Code treats as susceptible? If both answers are yes, the Housing Provisions give a short table of acceptable systems, AS 3660.1 says how each works, and a durable notice goes in the meter box.

This guide follows that chain clause by clause, then covers the state variations and Class 2 to 9 buildings. The checker in section 11 gives the answer for your building.

In one minute

• Part 3.4 applies where termites are a known risk and a primary building element is susceptible (Housing Provisions 3.4.1(1)). Elements made entirely of metal, concrete, masonry, fibre-reinforced cement, naturally termite-resistant timber (AS 3660.1 Appendix C) or preservative-treated timber (Appendix D) are considered not subject to attack (3.4.1(2)).

• The system is chosen from Table 3.4.2 and complies with AS 3660.1:2014, or has passed the tests in Section 5 of AS 3660.3 (3.4.2(1)). Slab penetrations and most joints need their own protection.

• 75 mm of exposed slab edge, 400 mm of subfloor clearance. An exposed edge shows at least 75 mm above finished ground, landscaping or paving (AS 3660.1 clause 4.4). A suspended floor that needs termite inspection has 400 mm under its lowest horizontal member (Housing Provisions Table 6.2.1b).

• A durable notice goes in the meter box or a similar prominent place, stating the system, its installation date, any chemical's life expectancy and the recommended inspections (3.4.3).

• Class 2 to 9 buildings follow Volume One B1D4, which calls up AS 3660.1 directly with the same materials list and notice. Queensland and the Northern Territory vary the rules, and termites are not considered a risk in Tasmania (section 9).

1. Where the termite rules sit in NCC 2025

The NCC treats termites as a structural action. The Performance Requirement for structural reliability lists termite actions among the actions a building must resist: H1P1(3) in Volume Two, B1P1(3) in Volume One.

For a Class 1 or 10 building, Volume Two H1D3(3) says compliance with Part 3.4 of the ABCB Housing Provisions satisfies H1P1 for termite risk management. Part 3.4 has three clauses: 3.4.1 says when a system is required, 3.4.2 what it must be, and 3.4.3 what the durable notice says.

The explanatory note to H1D3 is plain about the intent: a system that deters termites from entering a building by a concealed route. It will not stop termite activity on the site. AS 3660.1 works the same way, pairing partial measures with inspection zones so that termite workings end up in the open, where an inspection can find them (foreword).

Which edition. Schedule 2 of NCC 2025 calls up AS 3660.1:2014 Termite management, Part 1: New building work, incorporating Amendment 1, from Housing Provisions 3.4.1 and 3.4.2 and from Volume One B1D4. AS 3660.3:2014 sets the assessment criteria for systems. AS 3660.1 does not cover drywood termites (clause 1.1(b)).

2. When a house needs a termite management system

Housing Provisions 3.4.1(1) sets two conditions, and both must hold. The Class 1 or 10 building is constructed in an area where subterranean termites are known to present a potential risk of attack. And a primary building element is considered susceptible to termite attack. Garages, sheds and carports are Class 10, so they are covered too (see Class 10a sheds, garages and carports).

The risk area. The explanatory note to 3.4.1(1) says termites are not considered a risk in Tasmania and are a lesser risk in parts of Victoria. The appropriate authority may have records of termite activity and may be able to advise.

The primary building element. For Part 3.4 it is a member designed specifically to take part of the building loads. It includes roof, ceiling, floor, stairway or ramp and wall framing members, and their bracing members. Linings, cladding and joinery are not named. Queensland adds door jambs, window frames and reveals, architraves and skirtings (section 9).

Susceptible or not. Clause 3.4.1(2) lists the materials considered not subject to termite attack. An element made entirely of these, or of a combination of them, is not susceptible. An element of anything else is.

Material, 3.4.1(2)	What to check
(a) Steel, aluminium or other metals	Every member, including the roof and floor framing.
(b) Concrete	AS 3660.1 deems concrete elements termite resistant when they comply with AS 2870 or AS 3600 (3.2(b)).
(c) Masonry	Termites may still enter through mortar and other joints (explanatory note to 3.4.1(2)(c)).
(d) Fibre-reinforced cement	Listed without conditions.
(e) Timber, naturally termite resistant in accordance with Appendix C of AS 3660.1	Only the heartwood of species listed by botanical name; untreated sapwood is deemed susceptible (C2, C3). In the Northern Territory, only where Mastotermes darwiniensis is not prevalent.
(f) Timber, preservative treated in accordance with Appendix D of AS 3660.1	Treated to the AS 1604 series at the hazard level for its exposure: H2 inside above ground, H3 outside above ground, H4 and H5 outside in ground contact (D2). Cuts, drill holes, notches and planed surfaces need re-treating.

Housing Provisions 3.4.1(2), with the AS 3660.1:2014 conditions that apply to each material.

The explanatory note to 3.4.1(2) settles mixed construction: where some primary building elements are susceptible and the rest are termite resistant, only the susceptible elements need a termite management system. A steel-framed house with an untreated timber roof needs a system for the roof framing.

3. What the Housing Provisions accept

Where a system is required, 3.4.2(1) sets four conditions. It is selected appropriate to Table 3.4.2. It complies with AS 3660.1, or has been tested and passed the tests in Section 5 of AS 3660.3. It has a durable notice under 3.4.3. And any chemical used is on the appropriate authority's pesticides register.

Building element	Termite management system or component options
Concrete slab-on-ground: slab perimeter or external wall perimeter	Slab edge exposure; sheet material; granular material; chemical
Concrete slab-on-ground: penetrations, control joints, area beneath the slab (see note)	Sheet material; granular material; chemical
Suspended floors	Sheet material; granular material; chemical
Attachments to buildings	Termite management system to the attachment; inspection zone between attachment and building

NCC 2025 Housing Provisions Table 3.4.2, acceptable termite management systems and components. Note: the entire area beneath the slab must be treated when the slab-on-ground is not designed and constructed in accordance with AS 2870 or AS 3600.

Several options are components rather than complete systems. The explanatory note gives the example: a slab used as a component is not a complete system on its own, because its service penetrations need their own treatment. The components together form the full system.

The attachments row covers downpipes, service pipes, steps, verandahs, porches, access ramps, carports, trellises, decks, heated water systems, air-conditioners and the like (explanatory note).

4. Slab-on-ground: the slab, its edge and its penetrations

Section 4 of AS 3660.1 treats the slab as part of the system. It is designed and constructed to AS 2870 or AS 3600, and its edge is either exposed under clause 4.4 or protected with a sheet, granular or chemical system (4.3.1). Every penetration and joint has a system integrated with the slab, except a tied footing slab construction joint (4.2).

Joints. Vertical construction joints need a system whether or not the reinforcement runs through (4.3.2.1), and so do isolation, sawn and other movement control joints (4.3.2.3). An edge or footing beam placed integrally with the slab, or tied to it in accordance with AS 2870, needs no joint treatment if the footing is cleaned and the concrete compacted at the joint (4.3.2.2).

Penetrations. Service pipes through the slab are termite resistant and carry a system, such as a collar (4.3.2.4.1). A cast-in collar sits at least 40 mm below the top surface and 50 mm clear of reinforcing mesh and bar chairs (4.3.2.4.2). A sheet collar is a flange at least 15 mm wide and 20 mm high, fitted with no gap over 0.4 mm (5.3.6).

The exposed edge. Where slab edge exposure is part of the system, the outside face of the slab is exposed for at least 75 mm above finished ground, landscaping or paving (4.4). It is off the form, with no rough surface, honeycombing or ripples. It is not rendered, tiled, clad, or concealed by vapour barrier, plastic sheeting, flashings, adjoining structures, paving, soil or any other cover that could give termites a hidden path. The exposed edge is an inspection zone, and a ripple from a folded vapour barrier can hide a mud tube (notes to 4.4).

Plan the exposed edge with the finished levels, because turf, paving and landscaping laid later can bury it (AS 3660.1 clause 1.1, Note 7). Slab edge insulation is the other conflict. The Housing Provisions remind designers to choose a termite system compatible with it (explanatory note to 13.2.6). Insulation fixed over the edge conceals it, so that perimeter needs a sheet, granular or chemical system. Our insulation guide covers slab edge insulation.

5. Suspended floors: clearance and access for inspection

A suspended floor relies on people getting underneath to look. AS 3660.1 clause 3.3.2 asks for at least 400 mm between finished ground level and any structural component or obstruction, such as bearers, joists, plumbing or ducting. At the inside face of an external wall it may drop to 150 mm, provided the ground slopes away to give 400 mm within 2 m, and access for inspection still reaches the whole floor.

The Housing Provisions set the same figures through subfloor ventilation. Clause 6.2.1(1)(b) and Table 6.2.1b require 150 mm from the ground to the underside of the lowest horizontal member, and 400 mm where termite inspection is required. The table's notes limit the 400 mm to systems that need inspection, and allow 150 mm within 2 m of external walls on sloping sites.

Where the clearance is under 400 mm, AS 3660.1 asks for an underfloor system over the whole of the low area, unless the reduction of 3.3.2(b) applies (2.4). The other subfloor rules:

• Timber bearers, joists and bottom plates stay at least 25 mm from any vertical external masonry wall surface (3.3.3).

• Isolated piers, posts and stumps are accessible and capped with termite sheet (3.3.4). The cap projects at least 40 mm on all sides, edges turned down (5.3.4). A concrete stump or unperforated drawn or welded tubular metal pier, sealed at the top with its full perimeter accessible, can rely on a 75 mm vertical inspection zone instead (3.3.4(a)).

• Sheet on an external wall runs its full width, cavities included, and stays visible outside (5.3.2).

6. Sheet, granular and chemical systems

AS 3660.1 describes three families of system, used singly or in combination to form an integrated system (1.1). Systems and components the Standard does not detail are assessed to AS 3660.3 (1.5).

System	What it is	Key dimensions
Sheet (Section 5)	Metal sheet, grade 316 stainless steel mesh, PVC sheet or chemically treated sheet, each to its listed minimum (5.2)	Caps project 40 mm (5.3.4); collar flange 15 mm wide, 20 mm high (5.3.6); joint sheet allows 15 mm of movement with 35 mm of contact with the slab (5.3.7)
Granular (Section 6)	Termite-resistant particles tested to AS 3660.3 (6.2.1)	Mineral granules 75 mm deep, impregnated 40 mm (6.3.1); a 25 mm void around each penetration (6.3.3)
Chemical (Section 7)	A soil chemical registered by the pesticides registrar, applied to its approved label (7.1.1, 7.2)	Horizontal 150 mm wide, 50 mm deep (7.5.2); vertical 150 mm wide, to 50 mm below the top of the footing (7.5.3); external perimeter 150 mm wide, 80 mm deep (7.5.4)

The three system families of AS 3660.1:2014, summarised from the clauses cited. The Standard sets further conditions for each.

Chemical systems carry the most conditions. Under concealed and inaccessible areas they must be replenishable through a reticulation system (7.1.1). Hand-spraying under a slab happens on the same day as, and just before, the vapour barrier is laid (7.6(a)(ii)). Chemicals are not applied directly to concrete, timber or masonry (7.3(b)) or used as a surface treatment in wall cavities (7.3(c)).

7. Attachments and the building site

An inspection zone only works if nothing crosses it. AS 3660.1 clause 2.2 separates steps, verandas, porches, access ramps, carports, trellises, decks, hot-water systems, air conditioners, downpipes, service pipes and similar attachments from the building by at least 25 mm. Where an attachment abuts with no gap, the system is extended to it, and a plate over the gap must be detachable. Nothing may bridge or breach the system unless it has a system of its own (2.3).

The site is managed before work starts, under the normative Appendix F:

• Any nest of an economically important wood-feeding subterranean termite within the property boundaries, up to 50 m from the new work, has its colony eliminated before construction.

• Tree stumps, logs and exposed roots are removed from the building footprint.

• Timber offcuts, building debris and removable formwork are removed from the area to be treated.

8. The durable notice

Every required system ends with a notice. Housing Provisions 3.4.3(1) requires a durable notice permanently fixed to the building in a prominent location, such as in a meter box or the like. It indicates:

• The termite management system used.

• The date of installation of the system.

• Where a chemical is used, its life expectancy as listed on the appropriate authority's register label.

• The installer's or manufacturer's recommendations for the scope and frequency of future inspections for termite activity.

The explanatory note asks for a clearly written notice on a material that will not deteriorate or fade, in or near the electrical meter box, so future owners can read it. The notice is not the installer's paperwork: AS 3660.1's informative Appendix A recommends a separate Certificate of Installation (A3).

9. Queensland, the Northern Territory and Tasmania

Queensland. The Queensland definition of primary building element adds door jambs, window frames and reveals, architraves and skirtings. A steel-framed house with untreated timber jambs and skirtings has susceptible primary building elements.

Queensland adds a Performance Requirement, QLD H1P3: the measure has a design life of at least 50 years for a non-temporary Class 1 building, unless it is easily and readily accessible and can be replenished or replaced. QLD 3.4.1(4) and (5) carry that into Part 3.4. QLD 3.4.1(6) installs a chemical perimeter by trenching, treating and backfilling, under a concrete cover strip at least 50 mm thick and 300 mm wide. QLD Table 3.4.2 replaces the national table, rating slab edge exposure, termite shielding, stainless steel mesh, graded stone and chemicals for each footing system. Shielding suits suspended floors, not slabs.

Northern Territory. Naturally termite-resistant timber counts only in areas where Mastotermes darwiniensis is not prevalent (NT 3.4.1(2)(e)). Where it is prevalent, the system includes additional measures, and a chemical perimeter goes in a treated trench under a concrete strip at least 50 mm thick and 300 mm wide (NT 3.4.2(1)(d), (e)).

Tasmania. No variation applies, but the explanatory note to 3.4.1(1) says termites are not considered a risk there. Where termites are not a known risk the first condition is unmet and Part 3.4 does not apply, but the same note says the appropriate authority may be able to advise whether termite risk management is needed, so check locally.

10. Class 2 to 9 buildings

Volume One sets the requirement in one item of B1D4, the clause that sets the Standards for structural resistance. Where a primary building element is subject to attack by subterranean termites, B1D4(1)(i) calls up AS 3660.1, with the same list of materials considered not subject to attack and the same durable notice.

A Volume One primary building element is a member designed to take part of the loads specified in B1D3, and includes roof, ceiling, floor, stairway or ramp and wall framing. A building framed entirely in concrete and steel is outside the requirement. Our building classes guide sets out which class a building is.

Volume One has no Table 3.4.2, so the system is designed directly to AS 3660.1, whose scope is new buildings and new building work (1.1). Table F1D11 asks for 400 mm of subfloor clearance where systems that need inspection are installed (F1D11(1)(b)). Termite management systems are exempt from the non-combustible building element rules for Type A and B construction (C2D10(4)(d)). The Northern Territory variation to B1D4 adds measures where Mastotermes darwiniensis is prevalent.

11. Check your building

Choose the building class, the material of the primary building elements, the floor and the state or territory; Queensland and the Northern Territory may ask one more question. The headline says whether a system is required and the verdict gives the clause. The drawing shows your floor with the termite routes and the inspection zone, and the cards list what the Code accepts and the notice.

12. Worked examples

A brick veneer house on a slab with an untreated softwood frame. The frame is a primary building element and untreated timber is not on the 3.4.1(2) list, so Part 3.4 applies wherever termites are a known risk. One Table 3.4.2 package: slab edge exposure at the perimeter, a collar at every pipe, and sheet or granules at the control joints. The edge shows 75 mm above the finished paving all round (AS 3660.1 4.4), and the notice goes in the meter box (3.4.3).

The same house with an H2-treated pine frame and treated trusses. Appendix D treatment puts the timber on the list (3.4.1(2)(f)), and H2 is the level for timber inside and above ground. With every primary building element listed, Part 3.4 does not apply and no notice is needed.

A steel-framed house in Queensland with timber jambs and skirtings. The steel frame is not subject to attack (3.4.1(2)(a)), but in Queensland the jambs and skirtings are primary building elements too. Untreated, they need a system with a 50-year design life unless it is easily and readily accessible and can be replenished or replaced (QLD 3.4.1(4), (5)).

A timber-floored house on stumps on a sloping site. Untreated bearers and joists make a system necessary. The ground stays 400 mm below the bearers, falling to 150 mm at the external wall only where it rises over the last 2 m (3.3.2). Each stump takes a cap projecting 40 mm (5.3.4). If part of the subfloor has only 300 mm, that whole low area takes an underfloor system (2.4).

A house in Hobart. Termites are not considered a risk in Tasmania (note to 3.4.1(1)), so, unless the appropriate authority advises otherwise, an untreated timber frame needs no system and no notice, and a suspended floor needs 150 mm of clearance, not 400 mm (Table 6.2.1b).

13. Common mistakes

• Covering the exposed edge after handover. Paving, garden beds, render, tiles or slab edge insulation over the 75 mm edge remove the inspection zone (AS 3660.1 4.4). Set the finished levels so it stays exposed, or use another perimeter system.

• Treating masonry as a whole-house answer. The roof and floor framing are primary building elements too, and termites may enter through mortar joints (note to 3.4.1(2)(c)).

• Missing penetrations added later. Every pipe through the slab needs a collar or other treatment (4.3.2.4). A pipe moved after the pour can be treated with granules in a void around it (6.3.3).

• Decks, steps and downpipes against the wall. Without a 25 mm gap an attachment bridges the inspection zone unless the system is extended to it (2.2, 2.3).

• Cutting treated timber and leaving it. Cuts, drill holes, notches and planed surfaces need re-treating to keep the Appendix D protection (note to D2).

14. Where to read the source

NCC 2025 Volume Two H1P1 and H1D3, Housing Provisions Part 3.4, clause 6.2.1 and Table 6.2.1b with the Queensland and Northern Territory variations, and Volume One B1D4, C2D10 and F1D11 are free to read on the NCC website. AS 3660.1:2014 Termite management, Part 1: New building work (incorporating Amendment 1) is purchased from Standards Australia; this guide uses clauses 1.1 to 3.3, Sections 4 to 7 and Appendices A, C, D and F.

Inside AEC Assistant the Code text is searchable by clause, and on a paid plan the Standards are too. Ask whether a steel-framed house in Queensland with timber skirtings needs a termite management system and the answer comes back with the clause it was read from. This article is general guidance. The building surveyor or certifier for your project determines compliance.