Designer radiator: flat, smooth front or vertical?
In short
- A designer radiator stands out first by its front: a flat, smooth plate with side panels, instead of the profiled steel of a standard panel radiator.
- At the same size and type, a flat front costs about 14% more and gives about 7% less heat: in 1800 x 500 mm, 1,845 W for €450.22 against 1,980 W for €395.22 for the profiled version (Stelrad, type 22).
- In white, our flat and smooth-front designer radiators range from €244.99 (Belrad T20) to €602.91 (Stelrad Vertex Plan 2000 x 700 mm), incl. VAT. The flat Belrad version is the cheapest: €349.11 in 1800 x 500 mm.
A designer radiator heats with the same hot water as a standard radiator. What changes is the look: a flat or smooth front, often a vertical format, a discreet connection. That look has a price and a small cost in heat output. This guide puts figures on both for the designer radiators in our range, at the same size and type.
Last updated: October 2026. Prices recorded in the shop on 20/10/2026, incl. VAT.
What makes a radiator a designer radiator?
The front. A standard panel radiator shows profiled steel with vertical grooves. A flat panel radiator has a smooth front plate and side panels. Stelrad describes its Vertex Plan as a vertical radiator “with central connection and a flat front”, finished with a “decorative flat front plate and side panels”.
Three other features often come with it: the vertical format, which takes little wall width, the central bottom connection, which hides the pipes, and the colour. These are the designer families in our range:
| Family | Heights | Widths | Price incl. VAT |
|---|---|---|---|
| Stelrad Vertex Plan T22, flat front | 1,600 to 2,000 mm | 400 to 700 mm | €375.09 to €602.91 |
| Belrad Vertex Plan T22, flat front | 1,800 and 2,000 mm | 500 and 600 mm | €349.11 to €424.59 |
| Belrad T20, smooth front | 1,600 to 2,000 mm | 400 to 600 mm | €244.99 to €344.17 |
| Stelrad Vertex T22, profiled front | 1,800 and 2,000 mm | 500 and 600 mm | €395.22 to €439.91 |
| Double-sided oval or square, with sections | 1,800 mm | 472 to 608 mm | €239.12 to €302.02 |
How much does a flat front cost at the same size?
About 14% more. We sell the same type 22 vertical radiator in two finishes: the Stelrad Vertex with a profiled front and the Stelrad Vertex Plan with a flat front. Outputs come from Stelrad's documentation under the EN 442 standard (75 °C flow, 65 °C return, room at 20 °C).
| Size (H x W) | Vertex, profiled | Vertex Plan, flat | Price · output difference |
|---|---|---|---|
| 1800 x 500 mm | 1,980 W · €395.22 | 1,845 W · €450.22 | +14% · -7% |
| 2000 x 500 mm | 2,145 W · €429.60 | 1,980 W · €489.00 | +14% · -8% |
| 1800 x 600 mm | 2,376 W · €439.91 | 2,214 W · €501.28 | +14% · -7% |
Across the three sizes, the flat front adds €55 to €61 and removes 7 to 8% of output. In 1800 x 500 mm, one watt costs 20 cents with the profiled front and 24 cents with the flat front.
Flat or profiled: what changes in use?
Little day to day, but three points matter:
- Heat output: 7 to 8% less at the same size. For the same room, a flat front sometimes means the next size up.
- Weight: according to Stelrad, the 1,800 mm Vertex Plan type 22 weighs 105.3 kg per metre of width, against 88.8 kg for the Vertex. At 500 mm wide, that is about 53 kg against 44 kg, to be fixed on a wall that can take it.
- Depth: 102 mm for the Vertex Plan type 22, 100 mm for the Vertex, according to the same documentation. You will not see the difference.
A smooth front is easier to clean: there are no grooves for dust to settle in.
Stelrad or Belrad Vertex Plan: which one?
Belrad, if price matters most. Our range also has a Belrad type 22 Vertex Plan, cheaper at the same size. The outputs on its product pages are lower than Stelrad's for the same dimensions:
| Size (H x W) | Belrad Vertex Plan | Stelrad Vertex Plan |
|---|---|---|
| 1800 x 500 mm | 1,708 W · €349.11 (20.4 c/W) | 1,845 W · €450.22 (24.4 c/W) |
| 1800 x 600 mm | 2,049 W · €390.56 (19.1 c/W) | 2,214 W · €501.28 (22.6 c/W) |
| 2000 x 600 mm | 2,218 W · €424.59 (19.1 c/W) | 2,376 W · €546.93 (23.0 c/W) |
Even with fewer watts, the Belrad stays the cheapest per watt: about 19 to 20 cents, against 23 to 24 cents for the Stelrad.
What about a horizontal flat radiator?
Our range does not currently include a complete horizontal radiator with a flat front. The horizontal radiators are standard Belrad panel radiators with a profiled front. We sell smooth Belrad front panels separately in 55 sizes, from €39.83 to €102.57, and a lined version from €24.93 to €57.69. Their product page describes them as universal: check in store that they fit your radiator before buying.
Vertical, connection, colour: what to check?
Size first. Heights, widths and outputs of the vertical models are detailed in our vertical radiator guide.
Then the connection. According to Stelrad, the Vertex and the Vertex Plan have 4 female ½" connections, including a central bottom connection. For a neat central connection, we offer central connection kits from €35.53 to €44.44, straight or angled. Check the spacing of your pipes before buying.
Colour last. Our designer models come in white and matt black. Stelrad lists other colours made to order at the factory, but we do not stock them.
Frequently asked questions about designer radiators
Does a designer radiator heat less well?
Slightly, at the same size. According to Stelrad, the flat Vertex Plan type 22 gives 1,845 W in 1800 x 500 mm, against 1,980 W for the profiled Vertex, about 7% less.
What is the difference between a flat and a smooth-front radiator?
In our range, both mean a front without grooves. “Vertex Plan” is the name of the flat range by Stelrad and Belrad, “face lisse” (smooth front) the name of the Belrad T20 and matt black models.
Does a designer radiator work with a heat pump?
Yes, like any water radiator, but it gives less heat with cooler water. According to Stelrad, the 1800 x 500 mm type 22 Vertex Plan drops from 1,845 W to 946 W with 55 °C flow and 45 °C return. Have the sizing checked by your installer.
How much does a designer radiator cost?
In white in our range, from €244.99 for a smooth-front Belrad T20 to €602.91 for a 2000 x 700 mm Stelrad type 22 Vertex Plan, incl. VAT.
Is the thermostatic head included?
No. It is sold separately, like the central connection kit. Our guide to choosing and setting a thermostatic valve can help.
See designer radiators
Size, output and price are on every product page: see flat-front radiators, see smooth-front T20 radiators or see the profiled Vertex. Collection is at our shop in Schaerbeek.
Sources: Bati-Mat Shop range (prices incl. VAT recorded on 20/10/2026, Belrad outputs from the product pages) · Stelrad, technical documentation “STR-TD-NL” (Vertex and Vertex Plan sheets, EN 442 heat output tables, depths, weight per metre).