Best Practice for Installing a Skylight or Sun Tube in an Existing Home

Whether you’re looking to revitalise a dark hallway, brighten your bathroom, or upgrade a dated fixture, installing a skylight or sun tube can be one of the smartest investments you make in your home. Here’s a guide to best practices when considering a skylight or sun tube for your existing home.

Key Considerations

Sun tubes (also known as tubular skylights) and skylights are an excellent option for bringing natural light into tight or dark spaces like kitchens, hallways, wardrobes, and bathrooms.

Before installation, consider the following:

• Roof Orientation
  North-facing roofs are best for capturing consistent sunlight throughout the day in New Zealand.
• Tube Length & Bends
  At Suntrenz we don’t just install straight up to the easiest roof point. Instead we design each system to suit the home, often routing tubes through truss spaces to reach the sunniest and most effective part of the roof. This careful planning ensures optimal light performance where it’s needed most.
• Obstructions in the Roof Cavity
  Structural framing, HVAC ducting, or electrical wiring may affect placement options.
• Condensation & Moisture Control
  Suntrenz units are designed to minimise condensation and stay watertight. Condensation occurs when warm, moist air from inside rises into the cooler skylight tube. Our flashings include breather tabs that help regulate temperature and moisture for long-term performance.

One of the greatest advantages of sun tubes is their low-profile impact on both the roof and ceiling structure. Suntrenz sun tubes are designed specifically for New Zealand roof profiles and offer a seamless, aesthetic match while delivering the best in brightness and performance. Sun Tubes also require no structural modification, making them one of the best skylight choices for existing homes.

Rethinking Layout with a Skylight

Skylights and sun tubes aren’t just about adding light – they can completely reshape a space. For example, in bathrooms, removing a vertical window and replacing it with a skylight frees up a wall. This could allow for the luxury addition of a soaker tub or a his-and-hers vanity – transforming your bathroom’s functionality and style.

Example: This VELUX skylight installation showcases exposed trusses, eliminating the need for costly structural alterations.

Replacing a Leaking Skylight?

Skylight replacement is a major part of our work here at Suntrenz. Older skylights, particularly those that leak, can cause moisture damage, mould, and heat loss. Upgrading to a modern, double glazed and properly installed unit – will restore functionality and protect your home.

For the Best Advice & Installation

In New Zealand, structural changes like skylight installation often require compliance with the Building Code. It’s not just paperwork—it’s about ensuring safety, structural integrity, and avoiding future legal headaches. At Suntrenz, we take care of all required permits and council consents on your behalf, ensuring your project meets all regulatory standards.

Skylight installation isn’t just cutting a hole and popping in a window. It’s a multi-step process involving precise measuring, careful cutting, structural assessment, and most importantly, thorough sealing. Even small errors in placement or flashing can lead to major issues down the track.

Building Code & Consents

In most residential retrofit situations, skylight installation does not require building consent, provided the work doesn’t compromise structural elements or weathertightness in a way that would trigger consent under the Building Code. At Suntrenz, we assess this carefully on a case-by-case basis. Where structural elements are involved, we have a number of ways to work around or through the design, such as incorporating a truss into the feature and exposing it as a design element, which both maintains compliance and avoids the need for consent. And of course, if building consent is ever required, we’ll guide the customer through it or handle it on their behalf.

Here’s why it pays to hire a certified installer:

• Safety at Heights
  Installing skylights often involves working at height, where slips, unstable surfaces, or fragile materials can pose real risks. At Suntrenz, all our installers are fully trained and equipped to meet New Zealand’s safety regulations. While the legal responsibility for safe work practices sits primarily with the contractor, we believe homeowners also play a part by choosing reputable professionals who prioritise safety. After all, if safety isn’t front of mind, what does that suggest about the overall attitude toward the quality of installation?
• Heavy Materials & Special Tools
  Skylights can be heavy, awkward to handle, and often require specialist tools. A skilled installer ensures proper handling and accurate fitting.
• Correct Application & Materials
  Skylight installation isn’t just about getting the product on the roof — it’s about selecting the right solution for the situation and applying it correctly, using the appropriate materials and flashing systems for the specific roof type. With over 50 years of combined experience, the Suntrenz team knows how to think ahead — visualising the finished result before the job even begins. That forward thinking is why builders and roofers across New Zealand choose Suntrenz for their skylight installations.
• Warranty Protection
  Most manufacturers — including VELUX — don’t require a certified installer to maintain warranty coverage. However, they do require that the product is installed according to their specified guidelines and procedures. Failure to follow these can void the warranty. At Suntrenz, we specialise in VELUX skylight and tube skylight installations, strictly adhering to these guidelines to ensure your product performs as intended — and your warranty stays intact.
• Velux 10-Year Warranty
  VELUX skylight windows come with a 10-year manufacturing warranty — provided they are installed according to product specifications.

From navigating building consents to selecting the right product for your roof profile, we handle every step—so you don’t have to.

Book your free, no-obligation consultation today and discover how Suntrenz can help transform your home with natural light.