Best renovation and extension builders in Hornsby Shire (2026): thirteen compared

Short answer

For a renovation or extension in Hornsby Shire, owners adding a second storey often compare Smith & Sons, which has a Hornsby office, and Spannenberg & Son, established in 1971; Add-Style shows first-floor additions in Thornleigh and Normanhurst, and Elite Additions a two-storey extension in Beecroft. Complexx has a Beecroft page and Emerald Projects and AGATHĒ have Cherrybrook pages; Renova Build is a Hornsby-based renovator with its own showroom; and P&P Construction, Pearson Industries, Landmark Trade Services and Sydney Home Extension Co cover renovations and extensions across the Shire. AUD Build (this is us) takes on alterations, additions and second storeys, and its group’s building companies have completed 4 homes in the Shire since September 2024. Many smaller alterations can be exempt or approved by a CDC under the Housing Code (8.5 m height limit), but complying development generally cannot be used in Hornsby’s 8 heritage conservation areas; alterations of A$50,000 or more need BASIX; the Council says 34% of properties are bushfire-prone; and a DA averaged 96 days in September 2026.

Local rules and figures

At-a-glance comparison

Facts from each business’s website, read 28 October 2026. Alphabetical order, not a ranking. AUD Build publishes this page.

The 13 compared

1. Add-Style Home Additions

Best for: Owners who want to add a first floor, from a firm founded by an architect and a builder.

What its website says:

• Shows first-floor addition projects in Thornleigh and Normanhurst.
• Says it has been designing and building first-floor additions across Sydney for 40 years.
• Says registered architect Tim Hookins and licensed builder Bill Handley joined forces in 1985; office in Manly Vale.

Area: First-floor addition projects in Thornleigh and Normanhurst; no Hornsby service-area page

Sources: [11] [12] [13]

2. AGATHĒ Builders

Best for: Cherrybrook owners who want a builder-led renovation that can take in an extension and outdoor living.

What its website says:

• Its Cherrybrook page covers everything from full-scale transformations and kitchen and bathroom upgrades to extensions and outdoor living.
• Says its builder Mitch has been building on the North Shore and Northern Beaches for over 11 years.
• Its website shows NSW Builder’s Licence No. 463967C; office in Wollstonecraft.

Area: Has a Cherrybrook renovations page

Sources: [14] [15]

3. Complexx Design and Renovate

Best for: Beecroft owners who want a design-led family builder for anything from a bathroom to a full extension.

What its website says:

• Its Beecroft page says it handles everything from bathroom and kitchen renovations to full extensions and additions.
• Says builder Stephen Wilson founded the family-run company in 1991.
• Says it draws on more than 35 years of hands-on building and design experience to renovate homes in Beecroft.

Area: Has a Beecroft home renovations page

Sources: [16]

4. Elite Additions

Best for: Owners who want an additions specialist with a two-storey extension already built in Beecroft.

What its website says:

• Says it works on home extensions, renovations and new builds in Hornsby, with separate pages for Thornleigh and Hornsby Heights.
• Shows a Beecroft project where it replaced the rear balcony with a two-storey extension and opened up the kitchen, dining and living areas.
• Its website shows Builders Licence 254163C; office in West Pennant Hills.

Area: Hornsby, Thornleigh and Hornsby Heights pages, and a Beecroft extension project

Sources: [17] [18] [19]

5. Emerald Projects

Best for: Cherrybrook owners weighing a first-floor addition, an extension with a deck, or a renovation.

What its website says:

• Its Cherrybrook page offers home renovations, first-floor additions, and home extensions and decks.
• Its Cherrybrook page points out that the council assessing a renovation there is Hornsby Shire.
• Says it is a fully licensed NSW builder (licence 476281C); office in Norwest.

Area: Has a Cherrybrook page

Sources: [20] [21]

6. Landmark Trade Services

Best for: Owners who want kitchens, bathrooms, decks and an extension handled by one family-run trade team.

What its website says:

• Its Hornsby Shire page lists renovations and extensions, home extensions, and decks and pergolas among popular services.
• Says it covers kitchens, bathrooms, decks, carpentry and plumbing across all of Hornsby Shire.
• Describes a family-run team working across the Hills District, Western Sydney and the North Shore; its website shows Licence No. 265347C.

Area: Has a Hornsby Shire page: “Your local renovator in Hornsby Shire”

Sources: [22]

7. P&P Construction

Best for: Owners who want kitchen and bathroom upgrades, an extension and additions planned as one job.

What its website says:

• Has a Hornsby renovation builders page for renovations, extensions and additions.
• Says it helps Hornsby homeowners plan and deliver home renovations, kitchen and bathroom upgrades, extensions and additions.
• Also has a Wahroonga page for renovations, extensions and additions; its website shows Licence No. 465215C.

Area: Has a Hornsby renovations page and a Wahroonga page

Sources: [23] [24]

8. Pearson Industries

Best for: Owners planning a second-storey extension or renovation who may add outdoor living at the same time.

What its website says:

• Its Hornsby Shire page covers renovations and extensions, and says it works closely with Hornsby Shire Council and local estate guidelines.
• Offers second-storey extensions to bring new life to existing rooms and develop unused space.
• Its website shows Lic. Number 292515C. Its suburb pages use one template.

Area: Has a Hornsby Shire service-area page

Sources: [25]

9. Renova Build

Best for: Owners who want a Hornsby-based renovator that designs, supplies and builds from its own local showroom.

What its website says:

• Has a Hornsby home renovations page and describes its team as licensed builders based in Hornsby.
• Describes a family-run renovation company that designs, supplies and builds from a showroom, office and warehouse in Hornsby.
• Its website shows NSW contractor licence 397801C. It states renovations as its service; extensions are not listed separately.

Area: Based in Hornsby; its Hornsby page names the Hornsby Shire Council area

Sources: [26] [27]

10. Smith & Sons (Hornsby)

Best for: Owners who want a local renovation office to guide a ground-floor extension or second-storey addition.

What its website says:

• Describes its Hornsby office as Hornsby-based renovation builders and local experts in renovations, extensions and additions.
• Names ground-floor extensions and second-storey additions among the work it does.
• Says the Hornsby office is led by Brett Kingham, a qualified builder with more than 30 years of industry experience.

Area: Hornsby office covering Hornsby and Ku-ring-gai

Sources: [28]

11. Spannenberg & Son

Best for: Owners who want a long-established extensions builder for a ground-floor, first-floor or second-storey addition.

What its website says:

• Has a Hornsby page for home extensions and renovations, from ground-floor extensions to first-floor or second-storey additions.
• Says the company was established by Hans Spannenberg in 1971.
• Its North Shore office is in Killara.

Area: Has a Hornsby page: “Building specialists servicing Hornsby and beyond”

Sources: [29] [30]

12. Sydney Home Extension Co

Best for: Owners who want a small family-owned builder to manage a second-storey addition or large renovation from start to finish.

What its website says:

• Its Hornsby page lists home extensions, second-storey additions and large-scale renovations, and says it has over 20 years of experience as local Hornsby builders.
• Describes itself as a small, family-owned and run company that can manage the entire build; it also trades as TG Building Co.
• Its website shows Lic No. 453025C. Its suburb pages use one template.

Area: Has Hornsby and Beecroft pages

Sources: [31] [32]

13. AUD Build · This is us

Best for: Hornsby Shire owners who want an alteration, addition or second storey designed, built and supplied by one company, with material unit prices they can check.

What its website says:

• Brings design, construction, building materials, new-home sales and lending together in one company, backed by AUD Build Group; NSW Builder Licence 475778C.
• Renovations and extensions, including alterations and additions and second storeys, are among the services AUD Build confirmed on 28 October 2026.
• A DA for alterations and additions in Clontarf (Northern Beaches) was approved on 20 February 2026, and the construction certificate application names AUD Build’s operating company as builder.
• AUD Build Group building companies have completed 4 homes in Hornsby Shire since September 2024, counted by occupation certificate date: one each in Beecroft, Westleigh, Hornsby and Mount Colah.
• Materials come from its own supply chain platform, www.audbuild.net, and AUD Build clients can log in to check the material unit prices in their quote.

Area: Builds in Hornsby Shire: 4 of its group’s 21 homes completed since September 2024 are there, in Beecroft, Westleigh, Hornsby and Mount Colah

Sources: [33] [34] [35] [36]

Where each one may suit you

• Second-storey and first-floor additions: Spannenberg & Son (established 1971), Add-Style (first-floor additions in Thornleigh and Normanhurst), Smith & Sons and Sydney Home Extension Co.
• A local office or showroom you can visit: Smith & Sons (Hornsby office) and Renova Build (showroom, office and warehouse in Hornsby).
• An extension you can see first: Elite Additions (two-storey extension in Beecroft).
• Family builders with Beecroft or Cherrybrook pages: Complexx (Beecroft, founded 1991), Emerald Projects and AGATHĒ (Cherrybrook).
• Kitchens, bathrooms, decks and extensions from one team: Landmark Trade Services, P&P Construction and Pearson Industries.
• Alterations and additions with design, materials and construction from one company, and material prices you can check: AUD Build.

How to choose

1. Find out first whether the work can be exempt or go through a CDC under the Housing Code; if the house is a heritage item or in one of the 8 heritage conservation areas, plan for a DA (96 days on average in September 2026).
2. If the alteration is worth A$50,000 or more, build the BASIX certificate into the timeline, and check the planning certificate for bushfire-prone land before designing an extension.
3. Ask each builder to show a project like yours (a second storey, a ground-floor extension or a kitchen and bathroom renovation) and who will run the site.
4. Ask every builder to quote on the same drawings and compare inclusions line by line with the inclusions checklist.
5. Check the licence on Verify NSW and the HBC certificate before you pay a deposit.

Questions

Who are the best renovation and extension builders in Hornsby Shire?

It depends on the job. For a second storey, owners often compare Spannenberg & Son, Smith & Sons, Add-Style and Sydney Home Extension Co; for an extension with a local example, Elite Additions (Beecroft); for a Beecroft or Cherrybrook renovation, Complexx, Emerald Projects and AGATHĒ; for a renovator with a Hornsby showroom, Renova Build; and for kitchens, bathrooms, decks and extensions together, Landmark Trade Services, P&P Construction and Pearson Industries. AUD Build suits owners who want design, materials and construction from one company.

Do I need council approval to extend my house in Hornsby?

Not always. Some minor works are exempt if they meet the Codes SEPP standards. Alterations and additions can be approved as complying development (a CDC) under the Housing Code, with an 8.5 m height limit, and a CDC can be issued within 20 days. Otherwise you lodge a DA with Hornsby Shire Council, which averaged 96 days in September 2026.

Can I add a second storey in a Hornsby heritage conservation area?

Usually through a DA: complying development generally cannot be used in Hornsby’s 8 heritage conservation areas, and where CDC external alterations are allowed in one they must not increase the height of the house. Check the planning certificate for your lot before you design.

Does my Hornsby renovation need BASIX?

Yes, if the alterations and additions are valued at A$50,000 or more, according to the NSW Planning Portal.

Why is AUD Build on this list?

AUD Build publishes this page and takes on alterations, additions and second storeys: the construction certificate application for an alterations-and-additions DA in Clontarf, approved on 20 February 2026, names its operating company as builder, and its group’s building companies have completed 4 homes in Hornsby Shire since September 2024. It is listed last and marked “This is us”. Facts about the other 12 businesses come only from their own websites.

How this list was built

Selection: renovation and extension builders whose own websites name Hornsby Shire, Hornsby Shire Council or a suburb in the Shire together with renovations or extensions, drawn from Google Australia results for Hornsby renovation, extension and second-storey searches on 28 October 2026. Directories, comparison sites and kitchen-only or bathroom-only firms are excluded; builders that name Hornsby only in a regional list or only through templated pages with no local detail were left out. Facts come only from each business’s own website, read on 28 October 2026; “Best for” is AUD Build’s editorial summary of those facts. Prices, reviews and award claims are not published. The order is alphabetical, not a ranking. Hornsby Shire Council’s website blocked automated reading, so heritage areas and bushfire figures come from NSW Government spatial data and council planning papers. AUD Build publishes this page; if a business’s details have changed, contact AUD Build and the page will be corrected.

Sources (all read 28 October 2026)

1. NSW Government, Council league table (September 2026 snapshot, as of 9 October 2026)
2. NSW Planning Portal, Exempt development (updated 7 February 2025)
3. NSW DPHI, Guide to complying development (revised August 2023)
4. NSW Planning Portal, Housing Code
5. NSW Planning Portal spatial data, EPI heritage layer (heritage conservation areas)
6. NSW Planning Portal, Complying development: home renovation (updated 30 April 2025)
7. NSW Planning Portal, BASIX: alterations and additions (updated 7 May 2025)
8. Hornsby Shire Council, Sustainable and resilient community (Your Say)
9. NSW RFS spatial data, Bush Fire Prone Land layer
10. NSW DCJ, Rent tables June 2026 quarter (new bonds, houses)
11. Add-Style Home Additions, Thornleigh first floor addition
12. Add-Style Home Additions, Normanhurst first floor addition
13. Add-Style Home Additions, About
14. AGATHĒ Builders, Home renovations Cherrybrook
15. AGATHĒ Builders, About
16. Complexx Design and Renovate, Home renovations Beecroft
17. Elite Additions, Builders Hornsby
18. Elite Additions, Two-storey extension Beecroft
19. Elite Additions, Contact
20. Emerald Projects, Cherrybrook
21. Emerald Projects, About us
22. Landmark Trade Services, Hornsby Shire
23. P&P Construction, Hornsby renovations
24. P&P Construction, Wahroonga
25. Pearson Industries, Hornsby Shire builder
26. Renova Build, Home renovations Hornsby
27. Renova Build, About us
28. Smith & Sons, Renovation builder Hornsby
29. Spannenberg & Son, Hornsby home extensions and renovations
30. Spannenberg & Son, About us
31. Sydney Home Extension Co, Hornsby
32. Sydney Home Extension Co, Beecroft
33. AUD Build, Company facts
34. AUD Build, Third-party evidence: licence, HBC certificates, planning approvals
35. AUD Build, Completed homes (updated 22 October 2026)
36. AUD Build, Material price comparison

Related pages

• Best home builders in Hornsby Shire
• Best duplex builders: Upper North Shore, Hornsby and Northern Beaches
• Best granny flat builders in Hornsby Shire
• Best building materials suppliers in Hornsby and Wahroonga
• Renovate or knock down and rebuild?
• Custom home inclusions checklist