If you love where you live but need more space, a well planned house extension can transform daily life and add long term value. At Redwood Builders, we’ve spent the past decade delivering new space that looks like it has always belonged – from light filled kitchen – living expansions to second storey additions and smart garage conversions. This guide walks you through the key decisions, common pitfalls, and how we manage the process across the Kapiti Coast, Horowhenua, and the wider Wellington region.
Why extend rather than move
Moving can mean leaving a community you know, paying agency fees and legal costs, and compromising on location or layout. An extension lets you tailor your home to your lifestyle while keeping your neighbourhood, schools and commute. With careful design and a builder who understands local sites, winds and sun paths, you can unlock room to live without the upheaval of selling.
Popular extension options that work well locally
Single storey rear extension
Great for creating an open plan kitchen – dining – living area that connects to a deck or sheltered courtyard. We pay special attention to wind protection and indoor – outdoor flow that suits Kapiti and Wellington conditions.
Second storey addition
Ideal for views and site coverage constraints. Adding bedrooms and a bathroom upstairs frees up the ground floor for living. We coordinate engineering early so structure, bracing and tie – ins are seamless.
Side extension or pavilion
A glazed link to a new wing can preserve character while adding modern amenity. This works especially well on sites where sun angles and privacy need a sensitive approach.
Garage conversion
When the footprint already exists, converting to a home office, studio or guest suite can be efficient. We upgrade insulation, ventilation and fire – rated linings to meet code and comfort.
Bedroom – bathroom suite
A modest addition that creates a true main suite or a separate living space for multigenerational families can be life changing without altering the whole house.
Consents, planning and design
Most extensions require a building consent. Depending on your site and council rules, some may also need a resource consent, especially where height in relation to boundary, heritage overlays or natural hazards are involved. For a helpful overview of the statutory steps, see MBIE’s guide to the building process. We work with local designers and structural engineers to produce documentation that satisfies council while reflecting how you actually live.
Early planning considerations include:
- Site constraints: setbacks, easements, access for materials and scaffolding, and prevailing wind.
- Structure and services: how to support new loads, where to run drainage, water and power, and whether your switchboard needs an upgrade.
- Weathertightness: junctions between new and existing cladding, roof tie – ins and flashing details are critical in Wellington’s climate.
- Sun, views and privacy: window sizing and placement, eaves, skylights and brise – soleil can balance light, heat and neighbourly respect.
- Future flexibility: consider storage, acoustic separation, and how rooms could adapt as family needs change.
Budget and cost drivers
Every project is unique, so we price transparently from detailed scope and drawings rather than generic rates. The main drivers are:
- Complexity: second storey additions, steelwork, and significant structural alterations affect cost and programme.
- Size and specification: floor area, joinery performance, cladding type, and interior finishes make a measurable difference.
- Access and logistics: steep or constrained sites, limited parking, and protection of existing areas add time and care.
- Unknowns in older homes: hidden services, historic framing, and weather – tightness repairs are planned for with sensible contingencies.
We’ll discuss priorities early, present options, and show where investment has the biggest impact on daily comfort and resale value.
Our extension process
1) Discovery and advice
We start with a site visit to understand your goals, budget and timing. If you have concept plans, we review them for buildability and sequencing. If not, we can introduce trusted designers.
2) Pre – consent detailing and pricing
We collaborate with your designer and engineer to refine details that control cost – structure, cladding junctions, bathroom layouts, and window schedules. You receive a clear, itemised proposal.
3) Consents and pre – construction
We help coordinate documentation for council, line up specialist subcontractors, and prepare the site to safeguard your existing home. You’ll know the programme and key milestones before we start.
4) Build phase
As Licensed Building Practitioners, we manage carpentry, structural work, and all trades. You’ll have a dedicated point of contact for weekly updates. We protect lived – in areas, maintain safe access, and sequence works to minimise disruption.
5) Handover and aftercare
We complete council sign – offs, provide manuals and warranties, and stand behind our workmanship with both a 12 month maintenance guarantee and the Master Build 10 year guarantee for added peace of mind. You can learn more about the guarantee on the Registered Master Builders website.
Quality you can count on
Redwood Builders is recognised locally for straight communication, tidy sites and finishing details that endure Wellington weather. Our team coordinates leading subcontractors across Kapiti, Horowhenua and the wider region, and our project management keeps decisions simple and timelines realistic. We also look beyond code minimums – better insulation, thoughtful glazing, and ventilation strategies deliver quieter, warmer rooms that cost less to run.
Sustainability – small choices, big gains
Extensions are a prime opportunity to boost performance. Consider high performance windows, airtightness and ventilation, locally sourced timbers, and shading that controls summer heat without losing winter sun. We can suggest durable, low maintenance claddings and linings that suit sea air and exposed sites common along the coast.
Avoiding common pitfalls
- Under – scoping structural tie – ins: we engage engineering early so framing, bracing and fixings are right the first time.
- Forgetting services: we plan plumbing, drainage fall, and electrical capacity before linings go on.
- Poor weather detailing: our team prioritises roof – wall junctions, sill pans and flashings to keep water out long term.
- Living through construction without a plan: we schedule noisy or disruptive works, set up temporary kitchens where needed, and maintain safe, clean access.
- Rushing consent or inspections: we coordinate with council and keep documentation orderly so inspections are efficient and sign – off is smooth.
FAQs about house extensions
Do I need both a building consent and a resource consent?
Often you’ll only need a building consent, but some sites and designs trigger resource consent. We will flag likely requirements early and coordinate with your designer to streamline submissions.
How long will my extension take?
Timeframes vary with scope and complexity. A modest single storey addition is typically measured in months, while a major second storey or full reconfiguration takes longer. We provide a realistic programme before we begin and keep you updated weekly.
Can I live at home while you build?
In many cases, yes. We stage works, isolate areas, and maintain services to reduce disruption. If temporary relocation is advisable for safety or comfort, we will discuss the best timing and duration.
Will the new work blend with the existing house?
That’s our goal. We carefully match claddings and profiles where appropriate, align floor levels, and design junctions so the extension looks intentional rather than tacked on.
Do you manage all trades and inspections?
Yes. We coordinate subcontractors, book inspections, keep records tidy, and ensure workmanship meets or exceeds the Building Code and manufacturer requirements.
Ready to talk about your extension?
Whether you’re planning a compact kitchen – living expansion in Paraparaumu, a second storey addition in Waikanae, or a smart garage conversion in Wellington City, we can help from concept to completion. Call Redwood Builders on 022 351 4392 or get in touch to book a site visit. We work across the Kapiti Coast, Horowhenua and the wider Wellington region, and our workmanship is backed by the Master Build 10 year guarantee and our 12 month maintenance guarantee.
Redwood Builders – house extensions that feel like they’ve always been part of your home.