diff --git a/README.howto b/README.howto
index ca6a05ca..e53419e3 100644
--- a/README.howto
+++ b/README.howto
@@ -102,7 +102,7 @@ corresponding files puting hydro data in the directory work.hydro and
 urban data in the directory work.urban.
 
 As Curtis changed the directory structure in the last CVS versions you
-have to look in Construct/Main/main.cxx first and modify the directory
+have to look in BuildTiles/Main/main.cxx first and modify the directory
 names accordingly. (FE 30 arc-sec files should be in  work_base/DEM-30/
 
 Now we finished with data preparation and we can start generating
diff --git a/configure.in b/configure.in
index a47572b0..6e72f235 100644
--- a/configure.in
+++ b/configure.in
@@ -295,14 +295,16 @@ AC_OUTPUT( \
 	Makefile \
 	src/Makefile \
 	src/Include/Makefile \
-	src/Construct/Makefile \
-	src/Construct/Clipper/Makefile \
-	src/Construct/GenOutput/Makefile \
-	src/Construct/Match/Makefile \
-	src/Construct/Triangulate/Makefile \
-	src/Construct/Main/Makefile \
-	src/Construct/Osgb36/Makefile \
-	src/Construct/Parallel/Makefile \
+	src/Airports/Makefile \
+	src/Airports/GenAirports/Makefile \
+	src/BuildTiles/Makefile \
+	src/BuildTiles/Clipper/Makefile \
+	src/BuildTiles/GenOutput/Makefile \
+	src/BuildTiles/Match/Makefile \
+	src/BuildTiles/Triangulate/Makefile \
+	src/BuildTiles/Main/Makefile \
+	src/BuildTiles/Osgb36/Makefile \
+	src/BuildTiles/Parallel/Makefile \
 	src/Lib/Makefile \
 	src/Lib/Array/Makefile \
 	src/Lib/DEM/Makefile \
@@ -320,7 +322,6 @@ AC_OUTPUT( \
 	src/Prep/DemInfo/Makefile \
 	src/Prep/DemRaw2ascii/Makefile \
 	src/Prep/E00Lines/Makefile \
-	src/Prep/GenAirports/Makefile \
 	src/Prep/GSHHS/Makefile \
 	src/Prep/MergerClipper/Makefile \
 	src/Prep/ShapeFile/Makefile \
diff --git a/src/Airports/GenAirports/Makefile.am b/src/Airports/GenAirports/Makefile.am
index 01bed1f5..a353c40d 100644
--- a/src/Airports/GenAirports/Makefile.am
+++ b/src/Airports/GenAirports/Makefile.am
@@ -47,4 +47,4 @@ INCLUDES += \
 	-I$(top_srcdir) \
 	-I$(top_srcdir)/src \
 	-I$(top_srcdir)/src/Lib \
-	-I$(top_srcdir)/src/Construct
+	-I$(top_srcdir)/src/BuildTiles
diff --git a/src/BuildTiles/Clipper/Makefile.am b/src/BuildTiles/Clipper/Makefile.am
index 368e387f..7af44132 100644
--- a/src/BuildTiles/Clipper/Makefile.am
+++ b/src/BuildTiles/Clipper/Makefile.am
@@ -7,12 +7,12 @@ noinst_PROGRAMS = testclipper
 testclipper_SOURCES = testclipper.cxx
 
 testclipper_LDADD = \
-	$(top_builddir)/src/Construct/Clipper/libClipper.a \
-	$(top_builddir)/src/Construct/Osgb36/libOsgb36.a \
-	$(top_builddir)/src/Construct/Triangulate/libTriangulate.a \
+	$(top_builddir)/src/BuildTiles/Clipper/libClipper.a \
+	$(top_builddir)/src/BuildTiles/Osgb36/libOsgb36.a \
+	$(top_builddir)/src/BuildTiles/Triangulate/libTriangulate.a \
 	$(top_builddir)/src/Lib/Polygon/libPolygon.a \
 	$(top_builddir)/src/Lib/landcover/liblandcover.a \
 	$(top_builddir)/src/Lib/poly2tri/libpoly2tri.a \
 	-lsgbucket -lsgdebug -lsgmisc -lz -lgpc
 
-INCLUDES += -I$(top_srcdir)/src/Lib -I$(top_srcdir)/src/Construct
+INCLUDES += -I$(top_srcdir)/src/Lib -I$(top_srcdir)/src/BuildTiles
diff --git a/src/BuildTiles/GenOutput/Makefile.am b/src/BuildTiles/GenOutput/Makefile.am
index e0edb833..15b7f9b6 100644
--- a/src/BuildTiles/GenOutput/Makefile.am
+++ b/src/BuildTiles/GenOutput/Makefile.am
@@ -5,4 +5,4 @@ libGenOutput_a_SOURCES = genobj.cxx genobj.hxx
 INCLUDES += \
 	-I$(top_srcdir) \
 	-I$(top_srcdir)/src/Lib \
-	-I$(top_srcdir)/src/Construct
+	-I$(top_srcdir)/src/BuildTiles
diff --git a/src/BuildTiles/Main/Makefile.am b/src/BuildTiles/Main/Makefile.am
index d3f79f25..45e63cc2 100644
--- a/src/BuildTiles/Main/Makefile.am
+++ b/src/BuildTiles/Main/Makefile.am
@@ -5,11 +5,11 @@ fgfs_construct_SOURCES = \
 	main.cxx
 
 fgfs_construct_LDADD = \
-	$(top_builddir)/src/Construct/Clipper/libClipper.a \
-	$(top_builddir)/src/Construct/GenOutput/libGenOutput.a \
-	$(top_builddir)/src/Construct/Match/libMatch.a \
-	$(top_builddir)/src/Construct/Osgb36/libOsgb36.a \
-	$(top_builddir)/src/Construct/Triangulate/libTriangulate.a \
+	$(top_builddir)/src/BuildTiles/Clipper/libClipper.a \
+	$(top_builddir)/src/BuildTiles/GenOutput/libGenOutput.a \
+	$(top_builddir)/src/BuildTiles/Match/libMatch.a \
+	$(top_builddir)/src/BuildTiles/Osgb36/libOsgb36.a \
+	$(top_builddir)/src/BuildTiles/Triangulate/libTriangulate.a \
 	$(top_builddir)/src/Lib/Array/libArray.a \
 	$(top_builddir)/src/Lib/Geometry/libGeometry.a \
 	$(top_builddir)/src/Lib/Optimize/libOptimize.a \
@@ -26,4 +26,4 @@ fgfs_master_LDADD = -lsgbucket -lsgmisc
 INCLUDES += \
 	-I$(top_srcdir)/src \
 	-I$(top_srcdir)/src/Lib \
-	-I$(top_srcdir)/src/Construct
+	-I$(top_srcdir)/src/BuildTiles
diff --git a/src/BuildTiles/Match/Makefile.am b/src/BuildTiles/Match/Makefile.am
index 9d58c278..9e90d8b9 100644
--- a/src/BuildTiles/Match/Makefile.am
+++ b/src/BuildTiles/Match/Makefile.am
@@ -2,4 +2,4 @@ noinst_LIBRARIES = libMatch.a
 
 libMatch_a_SOURCES = match.cxx match.hxx
 
-INCLUDES += -I$(top_srcdir)/src/Lib -I$(top_srcdir)/src/Construct
+INCLUDES += -I$(top_srcdir)/src/Lib -I$(top_srcdir)/src/BuildTiles
diff --git a/src/BuildTiles/Parallel/Makefile.am b/src/BuildTiles/Parallel/Makefile.am
index 28d96884..06d92c09 100644
--- a/src/BuildTiles/Parallel/Makefile.am
+++ b/src/BuildTiles/Parallel/Makefile.am
@@ -13,4 +13,4 @@ fgfs_tools_client_LDADD = -lsgbucket -lsgmisc
 INCLUDES += \
 	-I$(top_srcdir)/src \
 	-I$(top_srcdir)/src/Lib \
-	-I$(top_srcdir)/src/Construct
+	-I$(top_srcdir)/src/BuildTiles
diff --git a/src/BuildTiles/Triangulate/Makefile.am b/src/BuildTiles/Triangulate/Makefile.am
index aa822d5e..cff5efa3 100644
--- a/src/BuildTiles/Triangulate/Makefile.am
+++ b/src/BuildTiles/Triangulate/Makefile.am
@@ -4,4 +4,4 @@ libTriangulate_a_SOURCES = \
 	triangle.cxx triangle.hxx \
 	trieles.cxx trieles.hxx
 
-INCLUDES += -I$(top_srcdir)/src/Lib -I$(top_srcdir)/src/Construct
+INCLUDES += -I$(top_srcdir)/src/Lib -I$(top_srcdir)/src/BuildTiles
diff --git a/src/Lib/Geometry/Makefile.am b/src/Lib/Geometry/Makefile.am
index 1daa89e3..6039743b 100644
--- a/src/Lib/Geometry/Makefile.am
+++ b/src/Lib/Geometry/Makefile.am
@@ -9,4 +9,4 @@ libGeometry_a_SOURCES = \
 INCLUDES += \
 	-I$(top_srcdir)/src \
 	-I$(top_srcdir)/src/Lib \
-	-I$(top_srcdir)/src/Construct
+	-I$(top_srcdir)/src/BuildTiles
diff --git a/src/Lib/Optimize/Makefile.am b/src/Lib/Optimize/Makefile.am
index 7afcae7e..d9866762 100644
--- a/src/Lib/Optimize/Makefile.am
+++ b/src/Lib/Optimize/Makefile.am
@@ -4,4 +4,4 @@ libOptimize_a_SOURCES = \
 	genfans.cxx genfans.hxx \
 	genstrips.cxx genstrips.hxx
 
-INCLUDES += -I$(top_srcdir)/src/Lib -I$(top_srcdir)/src/Construct
+INCLUDES += -I$(top_srcdir)/src/Lib -I$(top_srcdir)/src/BuildTiles
diff --git a/src/Makefile.am b/src/Makefile.am
index 83130fa1..151c965d 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -2,5 +2,6 @@ SUBDIRS = \
 	Include \
 	Lib \
 	Prep \
-	Construct \
+	Airports \
+	BuildTiles \
 	Utils
diff --git a/src/Prep/Makefile.am b/src/Prep/Makefile.am
index 41bfd8e5..d82d1223 100644
--- a/src/Prep/Makefile.am
+++ b/src/Prep/Makefile.am
@@ -3,7 +3,6 @@ SUBDIRS = \
 	DemInfo \
 	DemRaw2ascii \
 	E00Lines \
-	GenAirports \
 	GSHHS \
 	MergerClipper \
 	ShapeFile