Airtightness has always been fundamental to Passive Haus design, however, with a focus on thermal efficiency, it is now an objective on every UK building project. What role do external post boxes play in helping to reach airtightness standards and reduce heating bills?

What is Airtightness?

Airtightness is about eliminating the unintentional movement of air through gaps and cracks in the building. When a home, office or factory is airtight, heat loss is minimised, so it takes less energy to keep the building warm and comfortable. This is different to ventilation, where you intend to open the window to let fresh air circulate.

Airtightness cuts the financial and environmental cost of living and working in ambient temperatures. With fuel bills escalating, it is a strong selling point for any buyer.

When architects design airtight properties, they need to consider all the points where air leakage is likely. This includes junctions in the building’s structure and the type of material used. The standard of workmanship from trades also plays a vital role in fully insulating and sealing the building.

To reduce energy bills and carbon emissions, all new builds in the EU had to achieve near Zero Energy Building (nZEB) by 2020, with an ‘energy efficiency first’ approach to design and construction. What surprises us is that nearly all the modern developments we drive past, still seem to have front door letterboxes.

An Alternative to Front Door Letterboxes

Even a well-fitted front door letterbox, with brushed and internal and external flaps, will not prevent some air leakage out and draughts in. How can building developers continue to opt for this option, when there is a viable alternative – external post boxes?

Lockable, external post boxes can be wall-mounted or fixed to a gate post outside the property. This is an affordable means of improving the airtightness of the building. No need to cut into a solid front door and risk creating a gap where heat can escape.

Lockable, outdoor letterboxes are designed to be robust and withstand British weather. They include security features and come in a range of styles and finishes to appeal to all tastes and budgets. It’s a practical option that aids the achievement of energy efficiency goals.

Are Parcel Boxes a Better Option for Modern Builds?

The other consideration is whether letterboxes are still relevant. Would a larger parcel box be better suited for modern living? With the rise in online shopping, most households and businesses regularly receive packages that are too large to slide through letterboxes. An external, free-standing parcel post box could be a more practical option for residential or commercial properties.

With a parcel post box, there is no need to keep answering the door to delivery drivers, they can post your mail without disturbing you. When you are ready, simply unlock the hold and collect at your convenience. No driving to the sorting office to pick up. No risk of parcels being left on the doorstep where they could get soaked in the rain or grabbed by an opportunistic passer-by.

Zero Energy Buildings

The new EU target is Zero Energy Buildings (ZEB) by 2030. This aims to tighten the standards around airtightness testing and ensure that any energy used comes from renewable sources. ZEB is seen as an important step in reducing carbon emissions in the construction industry and contributing to the UK’s commitment to net-zero by 2050. Will this be the target that encourages property developers to opt for an outside letterbox or parcel mailbox as a standard feature of new builds?

Contact Letterbox 4 You on 01296 839401 to discuss the options for your building project. We supply high quality, European-made, wall-mounted and free-standing secure post boxes.