Every part of a conversion, three ways.

LiFePO4 9.7-13kg per 100Ah; AGM 25-30kg. The DIY/Victron component route.

• Mid

  Renogy Core Mini 100Ah LiFePO4

  Renogy

  9.7 kg✓ verified≈ £330

  Lightweight 100Ah LiFePO4, self-heating. Best weight-saver.

Unit + gas system; bottle is the real weight. Gas Safe sign-off.

• Premium

  Truma gas blown-air heater

  Truma

  5 kgest.≈ £900
  Needs qualified sign-off (gas/electrical)

  Only if you run gas. Needs flue + certification. Real weight is the bottle (full 6kg Calor ~12kg+).

HEAVY (~28kg) and roof-mounted — payload hit AND raised centre of gravity.

• Mid

  Dometic FreshJet 2200

  Dometic

  28 kgest.≈ £1,500

  Weight sits high — raises the centre of gravity.

  Compact rooftop unit, popular Truma alternative. Similar weight/power considerations.

Runs off battery, mounted low (keeps weight down). Big power draw.

• Premium

  Eberspacher Breezonic / under-bench 12V

  Eberspacher/Zeliox

  18 kgest.£2,200

  Weight sits high — raises the centre of gravity.

  12V DC air-con — runs off battery (no hook-up), mounted low (weight stays low). Needs serious LiFePO4.

EMPTY weight only. FULL = empty + capacity_l x 1kg. 1L = 1kg — the biggest hidden payload killer.

• Budget

  Jerry cans / portable (2x 20L)

  generic

  2 kgest.≈ £30

  40 L capacity — counts as 40 kg when full

  Lightest, flexible, no plumbing. 2kg empty but 42kg full. Refill anywhere. Great for weekenders.

• Mid

  Fiamma 70L onboard fresh tank

  Fiamma

  3 kgest.£58

  70 L capacity — counts as 70 kg when full

  Classic van fresh tank. 3kg empty but ~73kg FULL — dominates payload. Consider part-filling.

• Mid

  Underslung fresh tank (60-90L)

  CAK/generic

  5 kgest.≈ £180

  75 L capacity — counts as 75 kg when full

  Under-chassis, saves interior space. Empty ~5kg, full ~80kg — slung low (good CoG). Needs frost protection.

• Mid

  Grey waste tank (40-70L)

  generic

  4 kgest.≈ £120

  50 L capacity — counts as 50 kg when full

  Collects used water. Fills as fresh empties, so combined water weight stays ~constant in use.

Empty weight; holds its own water. Gas types need Gas Safe sign-off.

• Budget

  Truma Therme TT2 (5L electric)

  Truma

  2 kg✓ verified≈ £150

  5 L capacity — counts as 5 kg when full

  5L hot water for hands/dishes, 300W + uses air-heater warmth. Not enough for a shower. Empty ~2kg.

• Mid

  Truma electric water heater (14L)

  Truma

  3 kg✓ verified≈ £330

  14 L capacity — counts as 14 kg when full

  14L mains-electric, shower for two. Empty ~3kg, ~17kg full. Needs 230V/hook-up or big power.

• Premium

  Diesel water heater / combi (Autoterm Flow / Truma Combi)

  Autoterm/Truma

  7 kgest.≈ £900

  10 L capacity — counts as 10 kg when full

  Heats water (+ often air) off diesel. Best all-round off-grid hot water. Combi replaces a separate air heater.

• Premium

  Truma Ultrastore BGE 10 (gas+electric)

  Truma

  6 kgest.≈ £400

  10 L capacity — counts as 10 kg when full

  Needs qualified sign-off (gas/electrical)

  10L gas+electric combi — best for off-grid showering (gas heats without hook-up). Gas Safe sign-off.

Hardware only; REAL weight is the 70-100L+ tanks + water heater it forces (Cat 6).

• Premium

  Wet-room: tray + wet-wall + mixer + drain + extractor

  generic

  15 kgest.≈ £400

  Weight sits high — raises the centre of gravity.

  Enclosure hardware. Real weight is what it forces: 70-100L+ fresh+grey tanks + water heater (Cat 6). Needs waterproofing.

Heaviest toilet hardware but no waste-water weight — payload advantage for full-timers.

• Mid

  Budget separating composting (Boxio/OGO-style)

  Boxio/generic

  6 kgest.≈ £180

  Compact urine-separating toilet at a fraction of premium price. Lighter, smaller capacity.

• Premium

  Nature's Head / Air Head composting

  Nature's Head/Air Head

  13.2 kg✓ verified≈ £950

  No chemicals/black water, separates urine/solids, fan-vented. Heaviest hardware but no waste-water weight.

Hob light (~6kg); gas system real weight is the bottle (~14-17kg full).

• Budget

  Portable 2-burner camping stove

  Coleman/Campingaz

  4 kgest.≈ £45

  Stowable, no install, small canisters. Great for weekenders. No fixed gas system.

• Mid

  Smev 9222 / Dometic HSG 2370 hob+sink

  Dometic/Smev

  5.8 kg✓ verified≈ £250

  Most popular van hob+sink. Twin glass lids, piezo, flame-failure. Runs off gas system.

• Mid

  Dometic Smev PI8022 2-burner hob

  Dometic/Smev

  4.5 kgest.≈ £180

  Hob-only, glass lid, FFD, piezo/12V ignition. Pair with a separate sink.

Hardware; +bottle 14-17kg full. Vented drop-out locker + Gas Safe sign-off.

• Mid

  Gas system: bottle + regulator + vented locker + pipework + bubble tester

  Calor/generic

  4 kgest.≈ £180
  Needs qualified sign-off (gas/electrical)

  THE BOTTLE IS THE REAL WEIGHT: full 6kg Calor propane ~14-17kg (tare 7.7-9kg + 6kg gas). Vented drop-out locker + Gas Safe sign-off.

Light but needs 1500W+ — weight/cost moves to Cat 1 (Heavy electrics).

• Mid

  Single-zone portable induction hob

  generic/Nuvi

  3 kgest.≈ £60

  Gas-free, no CO, great air quality. Light hardware BUT needs 1500W+ inverter + big LiFePO4 (Cat 1).

• Premium

  Twin-zone induction hob

  generic

  4.5 kgest.≈ £160

  Two-ring induction. Only sensible with Heavy electrics (2000W+). Zero gas/flue/certification.

Heaviest insulation item BY DESIGN. Only ~40-50% coverage on large flat panels — do not over-apply.

• Premium

  Dodo DEADN Hex (low-weight)

  Dodo Mat

  5 kgest.≈ £110

  Lower-mass butyl — quiet drive without unnecessary weight. The payload-conscious deadening choice.

Battens + PIR + 12mm ply deck + finish. ~22kg per 8x4 sheet. 1-2 sheets.

• Budget

  12mm ply subfloor + battens + PIR

  generic

  30 kg✓ verified≈ £90

  Battens, PIR between, 12mm ply deck. ~22kg/sheet — floor is 1-2 sheets. 9mm on smaller vans saves weight.

SNEAKY HEAVY. 6mm ~12kg/sheet, 9mm ~17kg/sheet. 3-5 sheets = 36-85kg.

• Budget

  6mm ply wall/ceiling cladding (3-5 sheets)

  generic

  40 kg✓ verified≈ £120

  Lining panels. ~12kg/sheet; a van uses 3-5 sheets = 36-60kg. Where hidden weight adds up. 4-6mm keeps it down.

• Mid

  Tongue & groove cladding (ceiling)

  pine/poplar

  20 kgest.≈ £90

  Timber cladding for a classic ceiling. Poplar/lightweight species save weight vs pine.

• Premium

  Carpet lining / trim panels

  4-way stretch

  8 kgest.≈ £110

  4-way-stretch van carpet over ply or panels — light, hides curves, quick. Lightweight wall finish alternative.

Lightest sleeping option. BED ONLY — cannot carry passengers.

• Mid

  Lightweight fixed bed (aluminium extrusion)

  generic

  30 kgest.≈ £350

  Aluminium T-slot or thin-ply frame to cut weight. Good for payload-tight builds. Bed-only.

Mostly ply (see Cat 11). Full fit-out adds 60-120kg.

• Budget

  DIY ply cabinet carcasses

  DIY

  40 kgest.≈ £120

  Units from 12/15mm ply — bulk of furniture weight. Thinner ply/lightweight board where non-structural (Cat 11).

• Mid

  Lightweight board carcasses (poplar/hex-core)

  generic

  28 kgest.≈ £400

  Poplar ply or honeycomb/hex-core cuts cabinet weight substantially vs birch. The pro weight-saving trick.

Mounted high on the side. Heavier than people expect (~25kg).

• Budget

  Pull-out / drive-away fabric awning

  Vango/generic

  8 kgest.≈ £150

  Weight sits high — raises the centre of gravity.

  Cheaper, lighter, packs away (not permanently mounted). No fixed weight/drilling. Weekenders.

REAR overhang + rear-axle load + bike weight. Affects handling.

• Budget

  Rear door / towbar bike rack (2-4 bikes)

  Fiamma/Thule

  12 kgest.≈ £180

  Weight sits high — raises the centre of gravity.

  ~12kg empty + bike weight, all at the REAR — loads rear axle + overhang. Affects handling + door use.

  Check door/hinge rating

Frees interior space; significant REAR weight + a full wheel (Cat 15).

• Budget

  Rear-mounted spare wheel carrier

  generic

  12 kgest.≈ £150

  Frees interior space. Carrier + a full wheel (Cat 15) is significant REAR weight/overhang.

  Carrier + full wheel is significant rear weight

~0kg added, unlocks 200-750kg. THE fix for an over-limit build (if chassis qualifies). >3500kg = C1 licence.

• Budget

  Re-plate uprate — chassis already supports it

  SVTech/Van Weight Engineering

  0 kg✓ verified≈ £250

  Where chassis/axles allow it, a legal re-plate adds NO weight but unlocks 200-750kg for ~£160-£312. THE fix for over-limit. >3500kg = C1 licence + possible toll/speed changes.

  Depends on individual axle limits + wheel/tyre rating; 3850/4250 not always possible

Uprated-load-index tyres often required for a higher plate. A/T can LOWER load index — trap.

• Budget

  Uprated-load-index tyres (CrossClimate 121/112)

  Michelin/Continental

  4 kgest.≈ £600

  Higher-load-index tyres — often REQUIRED to legally support a higher plate. Minimal weight. All-season suits UK.

  Load index must match uprated axle weights

The only notable weight. Memory foam heavier; latex/lightweight foam saves weight.

• Budget

  DIY cut-to-size foam mattress (firm + topper)

  GB Foam/Foam Factory

  10 kgest.≈ £120

  Cut-to-fit firm PU base + softer topper — standard DIY route. Sectional foam doubles as seat cushions. Min 8cm. Lighter than memory foam.

• Mid

  Custom memory-foam / hybrid van mattress

  The Foam Shop/RoamRest

  15 kgest.≈ £300

  Made-to-measure for a proper sleep + exact fit. Heaviest soft-good (dense foam). Look for CertiPUR/Oeko-Tex.

• Premium

  Latex / lightweight comfort foam mattress

  foam specialist

  12 kgest.≈ £450

  Latex/lightweight comfort foam — breathable, temperature-regulating, durable, lighter than memory foam. Payload-conscious.

Light — but CONTENTS (your gear) are the real payload. Budget a gear reserve.

• Budget

  Hanging organisers, baskets, boxes, hooks

  generic

  3 kgest.≈ £60

  Soft/light storage. Adds up in bulk — but the CONTENTS (your gear) are the real weight; budget a gear reserve in payload.