The Dry House Weekly - Week 5

Yuri Gijselman
Aug 20
5 min read

Welcome to Week 5 of The Dry House Weekly.

After defining the climate‑first architecture — shaded perimeter corridors, deep eaves, and louvered façades — we now delve a bit deeper in the passive design and layer in MEP systems that are lightweight, modular, serviceable, and off‑grid ready.

Phase 5: MEP

Design intent

Before exploring the MEP systems, it’s important to establish the design philosophy that underpins The Dry House and supports its sustainable goals. Every decision is guided by strategies that reduce environmental impact, simplify construction, and ensure long-term adaptability.

Core Principles:

Minimize loads through passive design — optimize shading, ventilation, and orientation so systems can be smaller and more efficient.
Adopt fully dry, reversible assembly — use mechanical fasteners, press/crimp/compression fittings, and pre-terminated cables to allow easy installation, maintenance, and future upgrades.
Plan clear service lanes — keep all MEP runs visible and accessible within ventilated corridors and ceiling voids, using clipped panels for easy access.
Ensure off-grid readiness — integrate solar power with battery storage for base electrical loads, select efficient appliances, and design for water self-sufficiency through collection and reuse systems.

Passive (Cooling & Ventilation)

If you design the building to work with its environment, the mechanical systems can be smaller, simpler, and less reliant on energy and complex maintenance.

Climate-Responsive Architecture as the Foundation.

Before selecting a single fan, pump, or panel, we shaped the villa to harness the natural assets of its tropical location:

Shaded Perimeter Corridors – Acting as a “thermal buffer” between interiors and the elements, reducing direct solar gain and shielding walls, doors, and windows from heavy rain.
Deep Roof Overhangs & Louvers – Prevent most sun and rain from hitting glazing, lowering heat gain and reducing the need for ultra-tight weather seals.
Cross-Ventilation Layout – Rooms and corridors aligned to prevailing wind directions, ensuring a continuous breeze flows through living spaces.
Stack Effect Ventilation – Clerestory vents, ridge openings, and double-height zones allow hot air to rise and escape naturally.
Light-Colored, Low-Mass Surfaces – External materials reflect heat while interior finishes avoid thermal mass buildup, keeping rooms cooler during the day.
Vegetation Integration – Shaded courtyards, trellises, and surrounding greenery help cool incoming air before it reaches the living spaces.

Why Passive Comes First.

By embedding these strategies into the core architecture, The Dry House:

Minimizes active cooling demand — A/C is required only in bedrooms and the living room, and for limited hours.
Reduces electrical load — Smaller systems can be run off a solar + battery setup without oversizing.
Simplifies plumbing — Shading reduces water temperature rise in external pipes, easing material demands and prolonging lifespan.
Improves resilience — In case of a power outage, the house remains comfortable longer without relying on mechanical systems.

Only after this climate-first framework was in place did we size and select MEP systems — meaning every component is right-sized, modular, and dry-installed.

Mechanical (Cooling & Ventilation)

Strategy

Thermal comfort by design first (shading, cross‑ventilation, stack effect), then targeted cooling only where needed.

Systems

Split A/C units (bedrooms + living room only):
- Wall‑mounted, inverter type; pre‑charged line sets with flare connections (no brazing).
- Condensate handled via mechanically clipped HDPE drain to exterior soak trench or greywater line (as appropriate).
Ceiling fans (all other spaces):
- Low‑watt, high‑CFM units with wall controllers; mounted to pre‑fixed backing plates on the CLB/steel frame.
Background ventilation:
- Louvered openings and ridge/soffit vents; optional trickle vents with removable insect screens.

Dry‑Install Details

A/C brackets bolted to structure; vibration pads.
Line‑set routes in surface‑mounted cable/pipe trays; quick‑fit condensate unions.
No site foams or mastics; use EPDM gaskets in mechanical escutcheons.

Electrical (Solar‑First, Low‑Energy)

Supply & Generation

PV array on roof pergola/overhangs; MC4 plug connectors and rail‑mount clamps (no roof penetrations through primary waterproofing).
Hybrid inverter + LiFePO₄ battery bank sized for: lighting, fans, refrigeration, devices, and limited A/C hours.

Distribution

DIN‑rail main board with labeled MCBs/RCBOs; surge protection.
Surface‑mounted metal trunking and conduit with compression glands; all outlets on raised dado height along ventilated corridors to remain accessible.
LED lighting throughout (warm‑neutral 3000–3500K), low‑glare fixtures; plug‑and‑play drivers.

Dry‑Install Details

Pre‑terminated leads; WAGO‑type lever connectors inside junction boxes.
Screw‑fix luminaires to battens; no ceiling plastering.
External fixtures on stand‑off brackets to maintain rear ventilation.

Plumbing & Water (Potable, Grey, Rain)

Potable Water

Primary source: natural well (potable).
Modular filtration skid (sediment → activated carbon → UV if required), entirely manifold‑mounted with isolation valves.

Grey & Rainwater

Rainwater harvesting from permeable paved surfaces and roof to first‑flush diverter, then to storage tank; quick‑flange connections.
Greywater from showers/basins to a prefabricated treatment cartridge (or planted gravel bed) feeding toilet flushing + irrigation.

Blackwater

Option A: Sealed, prefabricated septic tank with mechanical compression couplings on inlet/outlet.
Option B (where permissible): Composting toilet modules (bolt‑down, vented) to eliminate blackwater handling.

Pipework (All Dry Methods)

Cold/Hot: PEX‑a/MLCP with press‑fit or compression fittings (no solder).
Waste: HDPE with electrofusion or mechanical couplers; solvent‑free.
Fixing: Pipe clips on continuous Unistrut rails; all runs visible/accessible behind removable wall/ceiling panels.

Controls & Monitoring

Simple first: wall controllers for fans/A/C; timer switches for exterior lights; float switches on tanks.
Optional smart layer: energy monitor on main; leak sensors in wet zones; tank level sensors; all low‑voltage, plug‑in gateways.

Commissioning Checklist (Site-Friendly)

Pressure test PEX at 1.5× operating pressure (record 2‑hour hold).
Megger test electrical circuits; verify RCD trip times.
Refrigerant: confirm pressures/temperatures against manufacturer charts.
Airflow: fan speeds, door undercuts/louver operation for cross‑vent.
PV: IV curve check; inverter startup log; battery state‑of‑health.
Water: flow rates, filter differential pressure, UV intensity (if used).
Grey/rain: backflow tests; flush diverter function; irrigation loop balance.

Kit of Parts (KoP)

The bathrooms are built using a kit of parts — a coordinated set of prefabricated, dry-install components designed for quick assembly, easy maintenance, and future upgrades.

Key Features:

Pre-finished wall and floor panels (moisture-resistant) fixed with mechanical clips — no tiles, grout, or plaster.
Modular plumbing assemblies with manifold connections and mechanical couplers — no solvent welding or site gluing.
Pre-assembled vanity, shower, and toilet modules that bolt into place, with all service connections accessible from adjacent corridors.
Replaceable fixtures — taps, mixers, and fittings can be swapped without disturbing finishes.
Integrated drainage kits with gaskets and compression seals instead of cement screeds.

Benefits:

Faster installation with minimal mess.
Easy future upgrades or repairs without demolition.
Improved water efficiency through pre-tested fixture packages.

Examples of other Kit of Parts Elements:

PV modules + rail clamps + MC4 loom
Hybrid inverter + battery rack (bolt‑down)
DIN‑rail board, MCBs/RCBOs, SPD, labeled ferrules
LED fixtures with quick‑connect drivers
Conduit/trunking, cable trays, Unistrut, clips
Split A/C (pre‑charged) + wall brackets + line sets + condensate kit
Ceiling fans + backing plates
PEX manifolds, press/compression fittings; HDPE waste with mechanical couplers
Filtration skid (sediment/carbon/UV), pumps, pressure tank
RWH first‑flush diverter, tank with screened vents/overflow
Prefab septic OR composting toilet module (as per code)

Operations & Maintenance (Low‑touch)

Filters: quarterly visual check; replace per ΔP/readiness.
Battery: quarterly firmware/SOH; keep ≤80–90% daily SOC target for longevity.
Fans/A/C: wipe blades/filters monthly; annual pro service.
Tanks: inspect screens, first‑flush chambers pre‑monsoon; sanitize annually.
Electrical: thermal scan of board annually; retorque terminals.

Performance Targets (For the Pilot)

Cooling: ≤ 15–20 kWh/day in peak season (bedrooms + living only).
Lighting: ≤ 2 W/m² average connected load.
Water: ≥ 60% toilet/irrigation demand from grey/rain sources.
Serviceability: 100% of valves, unions, junctions accessible without demolition.

Up Next (Week 6): Internal Finishes — Floors, Walls, and Ceilings. We’ll detail bamboo/coconut mat flooring, gypsum board assemblies rated for fixtures, and stretched‑fabric ceilings — all fully dry‑installed.

Welcome to Week 5 of The Dry House Weekly.

After defining the climate‑first architecture — shaded perimeter corridors, deep eaves, and louvered façades — we now delve a bit deeper in the passive design and layer in MEP systems that are lightweight, modular, serviceable, and off‑grid ready.

Phase 5: MEP

Design intent

Before exploring the MEP systems, it’s important to establish the design philosophy that underpins The Dry House and supports its sustainable goals. Every decision is guided by strategies that reduce environmental impact, simplify construction, and ensure long-term adaptability.

Core Principles:

Minimize loads through passive design — optimize shading, ventilation, and orientation so systems can be smaller and more efficient.

Adopt fully dry, reversible assembly — use mechanical fasteners, press/crimp/compression fittings, and pre-terminated cables to allow easy installation, maintenance, and future upgrades.

Plan clear service lanes — keep all MEP runs visible and accessible within ventilated corridors and ceiling voids, using clipped panels for easy access.

Ensure off-grid readiness — integrate solar power with battery storage for base electrical loads, select efficient appliances, and design for water self-sufficiency through collection and reuse systems.

Passive (Cooling & Ventilation)

If you design the building to work with its environment, the mechanical systems can be smaller, simpler, and less reliant on energy and complex maintenance.

Climate-Responsive Architecture as the Foundation.

Before selecting a single fan, pump, or panel, we shaped the villa to harness the natural assets of its tropical location:

Shaded Perimeter Corridors – Acting as a “thermal buffer” between interiors and the elements, reducing direct solar gain and shielding walls, doors, and windows from heavy rain.

Deep Roof Overhangs & Louvers – Prevent most sun and rain from hitting glazing, lowering heat gain and reducing the need for ultra-tight weather seals.

Cross-Ventilation Layout – Rooms and corridors aligned to prevailing wind directions, ensuring a continuous breeze flows through living spaces.

Stack Effect Ventilation – Clerestory vents, ridge openings, and double-height zones allow hot air to rise and escape naturally.

Light-Colored, Low-Mass Surfaces – External materials reflect heat while interior finishes avoid thermal mass buildup, keeping rooms cooler during the day.

Vegetation Integration – Shaded courtyards, trellises, and surrounding greenery help cool incoming air before it reaches the living spaces.

Why Passive Comes First.

By embedding these strategies into the core architecture, The Dry House:

Minimizes active cooling demand — A/C is required only in bedrooms and the living room, and for limited hours.

Reduces electrical load — Smaller systems can be run off a solar + battery setup without oversizing.

Simplifies plumbing — Shading reduces water temperature rise in external pipes, easing material demands and prolonging lifespan.

Improves resilience — In case of a power outage, the house remains comfortable longer without relying on mechanical systems.

Only after this climate-first framework was in place did we size and select MEP systems — meaning every component is right-sized, modular, and dry-installed.

Mechanical (Cooling & Ventilation)

Strategy

Thermal comfort by design first (shading, cross‑ventilation, stack effect), then targeted cooling only where needed.

Systems

Split A/C units (bedrooms + living room only):

Wall‑mounted, inverter type; pre‑charged line sets with flare connections (no brazing).

Condensate handled via mechanically clipped HDPE drain to exterior soak trench or greywater line (as appropriate).

Ceiling fans (all other spaces):

Low‑watt, high‑CFM units with wall controllers; mounted to pre‑fixed backing plates on the CLB/steel frame.

Background ventilation:

Louvered openings and ridge/soffit vents; optional trickle vents with removable insect screens.

Dry‑Install Details

A/C brackets bolted to structure; vibration pads.

Line‑set routes in surface‑mounted cable/pipe trays; quick‑fit condensate unions.

No site foams or mastics; use EPDM gaskets in mechanical escutcheons.

Electrical (Solar‑First, Low‑Energy)

Supply & Generation

PV array on roof pergola/overhangs; MC4 plug connectors and rail‑mount clamps (no roof penetrations through primary waterproofing).

Hybrid inverter + LiFePO₄ battery bank sized for: lighting, fans, refrigeration, devices, and limited A/C hours.

Distribution

DIN‑rail main board with labeled MCBs/RCBOs; surge protection.

Surface‑mounted metal trunking and conduit with compression glands; all outlets on raised dado height along ventilated corridors to remain accessible.

LED lighting throughout (warm‑neutral 3000–3500K), low‑glare fixtures; plug‑and‑play drivers.

Dry‑Install Details

Pre‑terminated leads; WAGO‑type lever connectors inside junction boxes.

Screw‑fix luminaires to battens; no ceiling plastering.

External fixtures on stand‑off brackets to maintain rear ventilation.

Plumbing & Water (Potable, Grey, Rain)

Potable Water

Primary source: natural well (potable).

Modular filtration skid (sediment → activated carbon → UV if required), entirely manifold‑mounted with isolation valves.

Grey & Rainwater

Rainwater harvesting from permeable paved surfaces and roof to first‑flush diverter, then to storage tank; quick‑flange connections.

Greywater from showers/basins to a prefabricated treatment cartridge (or planted gravel bed) feeding toilet flushing + irrigation.

Blackwater

Option A: Sealed, prefabricated septic tank with mechanical compression couplings on inlet/outlet.

Option B (where permissible): Composting toilet modules (bolt‑down, vented) to eliminate blackwater handling.

Pipework (All Dry Methods)

Cold/Hot: PEX‑a/MLCP with press‑fit or compression fittings (no solder).

Waste: HDPE with electrofusion or mechanical couplers; solvent‑free.

Fixing: Pipe clips on continuous Unistrut rails; all runs visible/accessible behind removable wall/ceiling panels.

Controls & Monitoring

Simple first: wall controllers for fans/A/C; timer switches for exterior lights; float switches on tanks.

Optional smart layer: energy monitor on main; leak sensors in wet zones; tank level sensors; all low‑voltage, plug‑in gateways.

Commissioning Checklist (Site-Friendly)

Pressure test PEX at 1.5× operating pressure (record 2‑hour hold).

Megger test electrical circuits; verify RCD trip times.

Refrigerant: confirm pressures/temperatures against manufacturer charts.

Airflow: fan speeds, door undercuts/louver operation for cross‑vent.

PV: IV curve check; inverter startup log; battery state‑of‑health.

Water: flow rates, filter differential pressure, UV intensity (if used).

Grey/rain: backflow tests; flush diverter function; irrigation loop balance.

Kit of Parts (KoP)